[PATCH 7/8] drm/edid: Constify lots of things

Alex Deucher alexdeucher at gmail.com
Mon Jan 27 22:38:15 UTC 2020


On Fri, Jan 24, 2020 at 3:03 PM Ville Syrjala
<ville.syrjala at linux.intel.com> wrote:
>
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
>
> Let's try to make a lot more stuff const in the edid parser.
>
> The "downside" is that we can no longer mangle the EDID in the
> middle of the parsing to apply quirks (drm_mode_detailed()).
> I don't really think mangling the blob itself is such a great
> idea anyway so I won't miss that part. But if we do want it
> back I guess we should do the mangling in one explicit place
> before we otherwise parse the EDID.
>
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

I generally agree, but are there any userspace expectations that they
will be getting a corrected EDID in some cases?

Alex

> ---
>  drivers/gpu/drm/drm_connector.c |   4 +-
>  drivers/gpu/drm/drm_edid.c      | 303 ++++++++++++++++++--------------
>  include/drm/drm_connector.h     |   4 +-
>  3 files changed, 176 insertions(+), 135 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> index f632ca05960e..92a5cd6ff6b1 100644
> --- a/drivers/gpu/drm/drm_connector.c
> +++ b/drivers/gpu/drm/drm_connector.c
> @@ -2377,7 +2377,7 @@ EXPORT_SYMBOL(drm_mode_put_tile_group);
>   * tile group or NULL if not found.
>   */
>  struct drm_tile_group *drm_mode_get_tile_group(struct drm_device *dev,
> -                                              char topology[8])
> +                                              const u8 topology[8])
>  {
>         struct drm_tile_group *tg;
>         int id;
> @@ -2407,7 +2407,7 @@ EXPORT_SYMBOL(drm_mode_get_tile_group);
>   * new tile group or NULL.
>   */
>  struct drm_tile_group *drm_mode_create_tile_group(struct drm_device *dev,
> -                                                 char topology[8])
> +                                                 const u8 topology[8])
>  {
>         struct drm_tile_group *tg;
>         int ret;
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index fd9b724067a7..8e76efe1654d 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -88,7 +88,7 @@
>
>  struct detailed_mode_closure {
>         struct drm_connector *connector;
> -       struct edid *edid;
> +       const struct edid *edid;
>         bool preferred;
>         u32 quirks;
>         int modes;
> @@ -1584,8 +1584,8 @@ MODULE_PARM_DESC(edid_fixup,
>                  "Minimum number of valid EDID header bytes (0-8, default 6)");
>
>  static void drm_get_displayid(struct drm_connector *connector,
> -                             struct edid *edid);
> -static int validate_displayid(u8 *displayid, int length, int idx);
> +                             const struct edid *edid);
> +static int validate_displayid(const u8 *displayid, int length, int idx);
>
>  static int drm_edid_block_checksum(const u8 *raw_edid)
>  {
> @@ -2207,41 +2207,41 @@ static bool is_detailed_timing_descriptor(const u8 d[18])
>         return d[0] != 0x00 || d[1] != 0x00;
>  }
>
> -typedef void detailed_cb(struct detailed_timing *timing, void *closure);
> +typedef void detailed_cb(const struct detailed_timing *timing, void *closure);
>
>  static void
> -cea_for_each_detailed_block(u8 *ext, detailed_cb *cb, void *closure)
> +cea_for_each_detailed_block(const u8 *ext, detailed_cb *cb, void *closure)
>  {
>         int i, n;
>         u8 d = ext[0x02];
> -       u8 *det_base = ext + d;
> +       const u8 *det_base = ext + d;
>
>         if (d < 4 || d > 127)
>                 return;
>
>         n = (127 - d) / 18;
>         for (i = 0; i < n; i++)
> -               cb((struct detailed_timing *)(det_base + 18 * i), closure);
> +               cb((const struct detailed_timing *)(det_base + 18 * i), closure);
>  }
>
>  static void
> -vtb_for_each_detailed_block(u8 *ext, detailed_cb *cb, void *closure)
> +vtb_for_each_detailed_block(const u8 *ext, detailed_cb *cb, void *closure)
>  {
>         unsigned int i, n = min((int)ext[0x02], 6);
> -       u8 *det_base = ext + 5;
> +       const u8 *det_base = ext + 5;
>
>         if (ext[0x01] != 1)
>                 return; /* unknown version */
>
>         for (i = 0; i < n; i++)
> -               cb((struct detailed_timing *)(det_base + 18 * i), closure);
> +               cb((const struct detailed_timing *)(det_base + 18 * i), closure);
>  }
>
>  static void
> -drm_for_each_detailed_block(u8 *raw_edid, detailed_cb *cb, void *closure)
> +drm_for_each_detailed_block(const u8 *raw_edid, detailed_cb *cb, void *closure)
>  {
> +       const struct edid *edid = (struct edid *)raw_edid;
>         int i;
> -       struct edid *edid = (struct edid *)raw_edid;
>
>         if (edid == NULL)
>                 return;
> @@ -2250,7 +2250,7 @@ drm_for_each_detailed_block(u8 *raw_edid, detailed_cb *cb, void *closure)
>                 cb(&(edid->detailed_timings[i]), closure);
>
>         for (i = 1; i <= raw_edid[0x7e]; i++) {
> -               u8 *ext = raw_edid + (i * EDID_LENGTH);
> +               const u8 *ext = raw_edid + (i * EDID_LENGTH);
>                 switch (*ext) {
>                 case CEA_EXT:
>                         cea_for_each_detailed_block(ext, cb, closure);
> @@ -2264,81 +2264,105 @@ drm_for_each_detailed_block(u8 *raw_edid, detailed_cb *cb, void *closure)
>         }
>  }
>
> +struct bool_closure {
> +       bool ret;
> +};
> +
>  static void
> -is_rb(struct detailed_timing *t, void *data)
> +is_rb(const struct detailed_timing *t, void *c)
>  {
> -       u8 *r = (u8 *)t;
> +       struct bool_closure *closure = c;
> +       const u8 *r = (const u8 *)t;
>
>         if (!is_display_descriptor(r, EDID_DETAIL_MONITOR_RANGE))
>                 return;
>
>         if (r[15] & 0x10)
> -               *(bool *)data = true;
> +               closure->ret = true;
>  }
>
>  /* EDID 1.4 defines this explicitly.  For EDID 1.3, we guess, badly. */
>  static bool
> -drm_monitor_supports_rb(struct edid *edid)
> +drm_monitor_supports_rb(const struct edid *edid)
>  {
>         if (edid->revision >= 4) {
> -               bool ret = false;
> -               drm_for_each_detailed_block((u8 *)edid, is_rb, &ret);
> -               return ret;
> +               struct bool_closure closure = {
> +                       .ret = false,
> +               };
> +
> +               drm_for_each_detailed_block((u8 *)edid, is_rb, &closure);
> +
> +               return closure.ret;
>         }
>
>         return ((edid->input & DRM_EDID_INPUT_DIGITAL) != 0);
>  }
>
> +struct data_closure {
> +       const u8 *data;
> +};
> +
>  static void
> -find_gtf2(struct detailed_timing *t, void *data)
> +do_find_gtf2(const struct detailed_timing *t, void *c)
>  {
> -       u8 *r = (u8 *)t;
> +       struct data_closure *closure = c;
> +       const u8 *r = (const u8 *)t;
>
>         if (!is_display_descriptor(r, EDID_DETAIL_MONITOR_RANGE))
>                 return;
>
>         if (r[10] == 0x02)
> -               *(u8 **)data = r;
> +               closure->data = r;
> +}
> +
> +static const u8 *
> +find_gtf2_descriptor(const struct edid *edid)
> +{
> +       struct data_closure closure = {};
> +
> +       drm_for_each_detailed_block((u8 *)edid, do_find_gtf2, &closure);
> +
> +       return closure.data;
>  }
>
>  /* Secondary GTF curve kicks in above some break frequency */
>  static int
> -drm_gtf2_hbreak(struct edid *edid)
> +drm_gtf2_hbreak(const struct edid *edid)
>  {
> -       u8 *r = NULL;
> -       drm_for_each_detailed_block((u8 *)edid, find_gtf2, &r);
> -       return r ? (r[12] * 2) : 0;
> +       const u8 *r = find_gtf2_descriptor(edid);
> +
> +       return r ? r[12] * 2 : 0;
>  }
>
>  static int
> -drm_gtf2_2c(struct edid *edid)
> +drm_gtf2_2c(const struct edid *edid)
>  {
> -       u8 *r = NULL;
> -       drm_for_each_detailed_block((u8 *)edid, find_gtf2, &r);
> +       const u8 *r = find_gtf2_descriptor(edid);
> +
>         return r ? r[13] : 0;
>  }
>
>  static int
> -drm_gtf2_m(struct edid *edid)
> +drm_gtf2_m(const struct edid *edid)
>  {
> -       u8 *r = NULL;
> -       drm_for_each_detailed_block((u8 *)edid, find_gtf2, &r);
> -       return r ? (r[15] << 8) + r[14] : 0;
> +       const u8 *r = find_gtf2_descriptor(edid);
> +
> +       return r ? (r[15] << 8) | r[14] : 0;
>  }
>
>  static int
> -drm_gtf2_k(struct edid *edid)
> +drm_gtf2_k(const struct edid *edid)
>  {
> -       u8 *r = NULL;
> -       drm_for_each_detailed_block((u8 *)edid, find_gtf2, &r);
> +       const u8 *r = find_gtf2_descriptor(edid);
> +
>         return r ? r[16] : 0;
>  }
>
>  static int
> -drm_gtf2_2j(struct edid *edid)
> +drm_gtf2_2j(const struct edid *edid)
>  {
> -       u8 *r = NULL;
> -       drm_for_each_detailed_block((u8 *)edid, find_gtf2, &r);
> +       const u8 *r = find_gtf2_descriptor(edid);
> +
>         return r ? r[17] : 0;
>  }
>
> @@ -2346,7 +2370,7 @@ drm_gtf2_2j(struct edid *edid)
>   * standard_timing_level - get std. timing level(CVT/GTF/DMT)
>   * @edid: EDID block to scan
>   */
> -static int standard_timing_level(struct edid *edid)
> +static int standard_timing_level(const struct edid *edid)
>  {
>         if (edid->revision >= 2) {
>                 if (edid->revision >= 4 && (edid->features & DRM_EDID_FEATURE_DEFAULT_GTF))
> @@ -2381,8 +2405,9 @@ bad_std_timing(u8 a, u8 b)
>   * and convert them into a real mode using CVT/GTF/DMT.
>   */
>  static struct drm_display_mode *
> -drm_mode_std(struct drm_connector *connector, struct edid *edid,
> -            struct std_timing *t)
> +drm_mode_std(struct drm_connector *connector,
> +            const struct edid *edid,
> +            const struct std_timing *t)
>  {
>         struct drm_device *dev = connector->dev;
>         struct drm_display_mode *m, *mode = NULL;
> @@ -2500,7 +2525,7 @@ drm_mode_std(struct drm_connector *connector, struct edid *edid,
>   */
>  static void
>  drm_mode_do_interlace_quirk(struct drm_display_mode *mode,
> -                           struct detailed_pixel_timing *pt)
> +                           const struct detailed_pixel_timing *pt)
>  {
>         int i;
>         static const struct {
> @@ -2543,12 +2568,12 @@ drm_mode_do_interlace_quirk(struct drm_display_mode *mode,
>   * return a new struct drm_display_mode.
>   */
>  static struct drm_display_mode *drm_mode_detailed(struct drm_device *dev,
> -                                                 struct edid *edid,
> -                                                 struct detailed_timing *timing,
> +                                                 const struct edid *edid,
> +                                                 const struct detailed_timing *timing,
>                                                   u32 quirks)
>  {
>         struct drm_display_mode *mode;
> -       struct detailed_pixel_timing *pt = &timing->data.pixel_data;
> +       const struct detailed_pixel_timing *pt = &timing->data.pixel_data;
>         unsigned hactive = (pt->hactive_hblank_hi & 0xf0) << 4 | pt->hactive_lo;
>         unsigned vactive = (pt->vactive_vblank_hi & 0xf0) << 4 | pt->vactive_lo;
>         unsigned hblank = (pt->hactive_hblank_hi & 0xf) << 8 | pt->hblank_lo;
> @@ -2590,9 +2615,9 @@ static struct drm_display_mode *drm_mode_detailed(struct drm_device *dev,
>                 return NULL;
>
>         if (quirks & EDID_QUIRK_135_CLOCK_TOO_HIGH)
> -               timing->pixel_clock = cpu_to_le16(1088);
> -
> -       mode->clock = le16_to_cpu(timing->pixel_clock) * 10;
> +               mode->clock = 1088 * 10;
> +       else
> +               mode->clock = le16_to_cpu(timing->pixel_clock) * 10;
>
>         mode->hdisplay = hactive;
>         mode->hsync_start = mode->hdisplay + hsync_offset;
> @@ -2613,14 +2638,14 @@ static struct drm_display_mode *drm_mode_detailed(struct drm_device *dev,
>         drm_mode_do_interlace_quirk(mode, pt);
>
>         if (quirks & EDID_QUIRK_DETAILED_SYNC_PP) {
> -               pt->misc |= DRM_EDID_PT_HSYNC_POSITIVE | DRM_EDID_PT_VSYNC_POSITIVE;
> +               mode->flags |= DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_NVSYNC;
> +       } else {
> +               mode->flags |= (pt->misc & DRM_EDID_PT_HSYNC_POSITIVE) ?
> +                       DRM_MODE_FLAG_PHSYNC : DRM_MODE_FLAG_NHSYNC;
> +               mode->flags |= (pt->misc & DRM_EDID_PT_VSYNC_POSITIVE) ?
> +                       DRM_MODE_FLAG_PVSYNC : DRM_MODE_FLAG_NVSYNC;
>         }
>
> -       mode->flags |= (pt->misc & DRM_EDID_PT_HSYNC_POSITIVE) ?
> -               DRM_MODE_FLAG_PHSYNC : DRM_MODE_FLAG_NHSYNC;
> -       mode->flags |= (pt->misc & DRM_EDID_PT_VSYNC_POSITIVE) ?
> -               DRM_MODE_FLAG_PVSYNC : DRM_MODE_FLAG_NVSYNC;
> -
>  set_size:
>         mode->width_mm = pt->width_mm_lo | (pt->width_height_mm_hi & 0xf0) << 4;
>         mode->height_mm = pt->height_mm_lo | (pt->width_height_mm_hi & 0xf) << 8;
> @@ -2644,7 +2669,7 @@ static struct drm_display_mode *drm_mode_detailed(struct drm_device *dev,
>
>  static bool
>  mode_in_hsync_range(const struct drm_display_mode *mode,
> -                   struct edid *edid, u8 *t)
> +                   const struct edid *edid, const u8 *t)
>  {
>         int hsync, hmin, hmax;
>
> @@ -2661,7 +2686,7 @@ mode_in_hsync_range(const struct drm_display_mode *mode,
>
>  static bool
>  mode_in_vsync_range(const struct drm_display_mode *mode,
> -                   struct edid *edid, u8 *t)
> +                   const struct edid *edid, const u8 *t)
>  {
>         int vsync, vmin, vmax;
>
> @@ -2677,7 +2702,7 @@ mode_in_vsync_range(const struct drm_display_mode *mode,
>  }
>
>  static u32
> -range_pixel_clock(struct edid *edid, u8 *t)
> +range_pixel_clock(const struct edid *edid, const u8 *t)
>  {
>         /* unspecified */
>         if (t[9] == 0 || t[9] == 255)
> @@ -2692,11 +2717,12 @@ range_pixel_clock(struct edid *edid, u8 *t)
>  }
>
>  static bool
> -mode_in_range(const struct drm_display_mode *mode, struct edid *edid,
> -             struct detailed_timing *timing)
> +mode_in_range(const struct drm_display_mode *mode,
> +             const struct edid *edid,
> +             const struct detailed_timing *timing)
>  {
>         u32 max_clock;
> -       u8 *t = (u8 *)timing;
> +       const u8 *t = (const u8 *)timing;
>
>         if (!mode_in_hsync_range(mode, edid, t))
>                 return false;
> @@ -2738,8 +2764,9 @@ static bool valid_inferred_mode(const struct drm_connector *connector,
>  }
>
>  static int
> -drm_dmt_modes_for_range(struct drm_connector *connector, struct edid *edid,
> -                       struct detailed_timing *timing)
> +drm_dmt_modes_for_range(struct drm_connector *connector,
> +                       const struct edid *edid,
> +                       const struct detailed_timing *timing)
>  {
>         int i, modes = 0;
>         struct drm_display_mode *newmode;
> @@ -2773,8 +2800,9 @@ void drm_mode_fixup_1366x768(struct drm_display_mode *mode)
>  }
>
>  static int
> -drm_gtf_modes_for_range(struct drm_connector *connector, struct edid *edid,
> -                       struct detailed_timing *timing)
> +drm_gtf_modes_for_range(struct drm_connector *connector,
> +                       const struct edid *edid,
> +                       const struct detailed_timing *timing)
>  {
>         int i, modes = 0;
>         struct drm_display_mode *newmode;
> @@ -2801,8 +2829,9 @@ drm_gtf_modes_for_range(struct drm_connector *connector, struct edid *edid,
>  }
>
>  static int
> -drm_cvt_modes_for_range(struct drm_connector *connector, struct edid *edid,
> -                       struct detailed_timing *timing)
> +drm_cvt_modes_for_range(struct drm_connector *connector,
> +                       const struct edid *edid,
> +                       const struct detailed_timing *timing)
>  {
>         int i, modes = 0;
>         struct drm_display_mode *newmode;
> @@ -2830,11 +2859,11 @@ drm_cvt_modes_for_range(struct drm_connector *connector, struct edid *edid,
>  }
>
>  static void
> -do_inferred_modes(struct detailed_timing *timing, void *c)
> +do_inferred_modes(const struct detailed_timing *timing, void *c)
>  {
>         struct detailed_mode_closure *closure = c;
> -       struct detailed_non_pixel *data = &timing->data.other_data;
> -       struct detailed_data_monitor_range *range = &data->data.range;
> +       const struct detailed_non_pixel *data = &timing->data.other_data;
> +       const struct detailed_data_monitor_range *range = &data->data.range;
>
>         if (!is_display_descriptor((const u8 *)timing, EDID_DETAIL_MONITOR_RANGE))
>                 return;
> @@ -2868,7 +2897,8 @@ do_inferred_modes(struct detailed_timing *timing, void *c)
>  }
>
>  static int
> -add_inferred_modes(struct drm_connector *connector, struct edid *edid)
> +add_inferred_modes(struct drm_connector *connector,
> +                  const struct edid *edid)
>  {
>         struct detailed_mode_closure closure = {
>                 .connector = connector,
> @@ -2876,18 +2906,20 @@ add_inferred_modes(struct drm_connector *connector, struct edid *edid)
>         };
>
>         if (version_greater(edid, 1, 0))
> -               drm_for_each_detailed_block((u8 *)edid, do_inferred_modes,
> +               drm_for_each_detailed_block((const u8 *)edid,
> +                                           do_inferred_modes,
>                                             &closure);
>
>         return closure.modes;
>  }
>
>  static int
> -drm_est3_modes(struct drm_connector *connector, struct detailed_timing *timing)
> +drm_est3_modes(struct drm_connector *connector,
> +              const struct detailed_timing *timing)
>  {
>         int i, j, m, modes = 0;
>         struct drm_display_mode *mode;
> -       u8 *est = ((u8 *)timing) + 6;
> +       const u8 *est = ((const u8 *)timing) + 6;
>
>         for (i = 0; i < 6; i++) {
>                 for (j = 7; j >= 0; j--) {
> @@ -2912,7 +2944,7 @@ drm_est3_modes(struct drm_connector *connector, struct detailed_timing *timing)
>  }
>
>  static void
> -do_established_modes(struct detailed_timing *timing, void *c)
> +do_established_modes(const struct detailed_timing *timing, void *c)
>  {
>         struct detailed_mode_closure *closure = c;
>
> @@ -2931,7 +2963,8 @@ do_established_modes(struct detailed_timing *timing, void *c)
>   * (defined above).  Tease them out and add them to the global modes list.
>   */
>  static int
> -add_established_modes(struct drm_connector *connector, struct edid *edid)
> +add_established_modes(struct drm_connector *connector,
> +                     const struct edid *edid)
>  {
>         struct drm_device *dev = connector->dev;
>         unsigned long est_bits = edid->established_timings.t1 |
> @@ -2962,19 +2995,19 @@ add_established_modes(struct drm_connector *connector, struct edid *edid)
>  }
>
>  static void
> -do_standard_modes(struct detailed_timing *timing, void *c)
> +do_standard_modes(const struct detailed_timing *timing, void *c)
>  {
>         struct detailed_mode_closure *closure = c;
> -       struct detailed_non_pixel *data = &timing->data.other_data;
> +       const struct detailed_non_pixel *data = &timing->data.other_data;
>         struct drm_connector *connector = closure->connector;
> -       struct edid *edid = closure->edid;
> +       const struct edid *edid = closure->edid;
>         int i;
>
>         if (!is_display_descriptor((const u8 *)timing, EDID_DETAIL_STD_MODES))
>                 return;
>
>         for (i = 0; i < 6; i++) {
> -               struct std_timing *std = &data->data.timings[i];
> +               const struct std_timing *std = &data->data.timings[i];
>                 struct drm_display_mode *newmode;
>
>                 newmode = drm_mode_std(connector, edid, std);
> @@ -2994,7 +3027,8 @@ do_standard_modes(struct detailed_timing *timing, void *c)
>   * GTF or CVT. Grab them from @edid and add them to the list.
>   */
>  static int
> -add_standard_modes(struct drm_connector *connector, struct edid *edid)
> +add_standard_modes(struct drm_connector *connector,
> +                  const struct edid *edid)
>  {
>         int i, modes = 0;
>         struct detailed_mode_closure closure = {
> @@ -3023,18 +3057,18 @@ add_standard_modes(struct drm_connector *connector, struct edid *edid)
>  }
>
>  static int drm_cvt_modes(struct drm_connector *connector,
> -                        struct detailed_timing *timing)
> +                        const struct detailed_timing *timing)
>  {
>         int i, j, modes = 0;
>         struct drm_display_mode *newmode;
>         struct drm_device *dev = connector->dev;
> -       struct cvt_timing *cvt;
>         const int rates[] = { 60, 85, 75, 60, 50 };
>         const u8 empty[3] = { 0, 0, 0 };
>
>         for (i = 0; i < 4; i++) {
>                 int uninitialized_var(width), height;
> -               cvt = &(timing->data.other_data.data.cvt[i]);
> +               const struct cvt_timing *cvt =
> +                       &timing->data.other_data.data.cvt[i];
>
>                 if (!memcmp(cvt->code, empty, 3))
>                         continue;
> @@ -3072,7 +3106,7 @@ static int drm_cvt_modes(struct drm_connector *connector,
>  }
>
>  static void
> -do_cvt_mode(struct detailed_timing *timing, void *c)
> +do_cvt_mode(const struct detailed_timing *timing, void *c)
>  {
>         struct detailed_mode_closure *closure = c;
>
> @@ -3083,7 +3117,8 @@ do_cvt_mode(struct detailed_timing *timing, void *c)
>  }
>
>  static int
> -add_cvt_modes(struct drm_connector *connector, struct edid *edid)
> +add_cvt_modes(struct drm_connector *connector,
> +             const struct edid *edid)
>  {
>         struct detailed_mode_closure closure = {
>                 .connector = connector,
> @@ -3101,7 +3136,7 @@ add_cvt_modes(struct drm_connector *connector, struct edid *edid)
>  static void fixup_detailed_cea_mode_clock(struct drm_display_mode *mode);
>
>  static void
> -do_detailed_mode(struct detailed_timing *timing, void *c)
> +do_detailed_mode(const struct detailed_timing *timing, void *c)
>  {
>         struct detailed_mode_closure *closure = c;
>         struct drm_display_mode *newmode;
> @@ -3137,8 +3172,8 @@ do_detailed_mode(struct detailed_timing *timing, void *c)
>   * @quirks: quirks to apply
>   */
>  static int
> -add_detailed_modes(struct drm_connector *connector, struct edid *edid,
> -                  u32 quirks)
> +add_detailed_modes(struct drm_connector *connector,
> +                  struct edid *edid, u32 quirks)
>  {
>         struct detailed_mode_closure closure = {
>                 .connector = connector,
> @@ -3173,9 +3208,10 @@ add_detailed_modes(struct drm_connector *connector, struct edid *edid,
>  /*
>   * Search EDID for CEA extension block.
>   */
> -static u8 *drm_find_edid_extension(const struct edid *edid, int ext_id)
> +static const u8 *drm_find_edid_extension(const struct edid *edid,
> +                                        int ext_id)
>  {
> -       u8 *edid_ext = NULL;
> +       const u8 *edid_ext = NULL;
>         int i;
>
>         /* No EDID or EDID extensions */
> @@ -3184,7 +3220,7 @@ static u8 *drm_find_edid_extension(const struct edid *edid, int ext_id)
>
>         /* Find CEA extension */
>         for (i = 0; i < edid->extensions; i++) {
> -               edid_ext = (u8 *)edid + EDID_LENGTH * (i + 1);
> +               edid_ext = (const u8 *)edid + EDID_LENGTH * (i + 1);
>                 if (edid_ext[0] == ext_id)
>                         break;
>         }
> @@ -3196,19 +3232,19 @@ static u8 *drm_find_edid_extension(const struct edid *edid, int ext_id)
>  }
>
>
> -static u8 *drm_find_displayid_extension(const struct edid *edid)
> +static const u8 *drm_find_displayid_extension(const struct edid *edid)
>  {
>         return drm_find_edid_extension(edid, DISPLAYID_EXT);
>  }
>
> -static u8 *drm_find_cea_extension(const struct edid *edid)
> +static const u8 *drm_find_cea_extension(const struct edid *edid)
>  {
>         int ret;
>         int idx = 1;
>         int length = EDID_LENGTH;
> -       struct displayid_block *block;
> -       u8 *cea;
> -       u8 *displayid;
> +       const struct displayid_block *block;
> +       const u8 *cea;
> +       const u8 *displayid;
>
>         /* Look for a top level CEA extension block */
>         cea = drm_find_edid_extension(edid, CEA_EXT);
> @@ -4315,28 +4351,30 @@ drm_parse_hdmi_vsdb_audio(struct drm_connector *connector, const u8 *db)
>  }
>
>  static void
> -monitor_name(struct detailed_timing *t, void *data)
> +monitor_name(const struct detailed_timing *t, void *c)
>  {
> +       struct data_closure *closure = c;
> +
>         if (!is_display_descriptor((const u8 *)t, EDID_DETAIL_MONITOR_NAME))
>                 return;
>
> -       *(u8 **)data = t->data.other_data.data.str.str;
> +       closure->data = t->data.other_data.data.str.str;
>  }
>
>  static int get_monitor_name(struct edid *edid, char name[13])
>  {
> -       char *edid_name = NULL;
> +       struct data_closure closure = {};
>         int mnl;
>
>         if (!edid || !name)
>                 return 0;
>
> -       drm_for_each_detailed_block((u8 *)edid, monitor_name, &edid_name);
> -       for (mnl = 0; edid_name && mnl < 13; mnl++) {
> -               if (edid_name[mnl] == 0x0a)
> +       drm_for_each_detailed_block((const u8 *)edid, monitor_name, &closure);
> +       for (mnl = 0; closure.data && mnl < 13; mnl++) {
> +               if (closure.data[mnl] == 0x0a)
>                         break;
>
> -               name[mnl] = edid_name[mnl];
> +               name[mnl] = closure.data[mnl];
>         }
>
>         return mnl;
> @@ -4386,11 +4424,9 @@ static void clear_eld(struct drm_connector *connector)
>  static void drm_edid_to_eld(struct drm_connector *connector, struct edid *edid)
>  {
>         uint8_t *eld = connector->eld;
> -       u8 *cea;
> -       u8 *db;
> +       const u8 *cea;
>         int total_sad_count = 0;
>         int mnl;
> -       int dbl;
>
>         clear_eld(connector);
>
> @@ -4425,8 +4461,8 @@ static void drm_edid_to_eld(struct drm_connector *connector, struct edid *edid)
>                 }
>
>                 for_each_cea_db(cea, i, start, end) {
> -                       db = &cea[i];
> -                       dbl = cea_db_payload_len(db);
> +                       const u8 *db = &cea[i];
> +                       int dbl = cea_db_payload_len(db);
>
>                         switch (cea_db_tag(db)) {
>                                 int sad_count;
> @@ -4484,7 +4520,7 @@ int drm_edid_to_sad(struct edid *edid, struct cea_sad **sads)
>  {
>         int count = 0;
>         int i, start, end, dbl;
> -       u8 *cea;
> +       const u8 *cea;
>
>         cea = drm_find_cea_extension(edid);
>         if (!cea) {
> @@ -4503,7 +4539,7 @@ int drm_edid_to_sad(struct edid *edid, struct cea_sad **sads)
>         }
>
>         for_each_cea_db(cea, i, start, end) {
> -               u8 *db = &cea[i];
> +               const u8 *db = &cea[i];
>
>                 if (cea_db_tag(db) == AUDIO_BLOCK) {
>                         int j;
> @@ -4514,7 +4550,7 @@ int drm_edid_to_sad(struct edid *edid, struct cea_sad **sads)
>                         if (!*sads)
>                                 return -ENOMEM;
>                         for (j = 0; j < count; j++) {
> -                               u8 *sad = &db[1 + j * 3];
> +                               const u8 *sad = &db[1 + j * 3];
>
>                                 (*sads)[j].format = (sad[0] & 0x78) >> 3;
>                                 (*sads)[j].channels = sad[0] & 0x7;
> @@ -4635,7 +4671,7 @@ EXPORT_SYMBOL(drm_av_sync_delay);
>   */
>  bool drm_detect_hdmi_monitor(struct edid *edid)
>  {
> -       u8 *edid_ext;
> +       const u8 *edid_ext;
>         int i;
>         int start_offset, end_offset;
>
> @@ -4673,7 +4709,7 @@ EXPORT_SYMBOL(drm_detect_hdmi_monitor);
>   */
>  bool drm_detect_monitor_audio(struct edid *edid)
>  {
> -       u8 *edid_ext;
> +       const u8 *edid_ext;
>         int i, j;
>         bool has_audio = false;
>         int start_offset, end_offset;
> @@ -5017,13 +5053,13 @@ u32 drm_add_display_info(struct drm_connector *connector, const struct edid *edi
>         return quirks;
>  }
>
> -static int validate_displayid(u8 *displayid, int length, int idx)
> +static int validate_displayid(const u8 *displayid, int length, int idx)
>  {
>         int i;
>         u8 csum = 0;
> -       struct displayid_hdr *base;
> +       const struct displayid_hdr *base;
>
> -       base = (struct displayid_hdr *)&displayid[idx];
> +       base = (const struct displayid_hdr *)&displayid[idx];
>
>         DRM_DEBUG_KMS("base revision 0x%x, length %d, %d %d\n",
>                       base->rev, base->bytes, base->prod_id, base->ext_count);
> @@ -5041,7 +5077,7 @@ static int validate_displayid(u8 *displayid, int length, int idx)
>  }
>
>  static struct drm_display_mode *drm_mode_displayid_detailed(struct drm_device *dev,
> -                                                           struct displayid_detailed_timings_1 *timings)
> +                                                           const struct displayid_detailed_timings_1 *timings)
>  {
>         struct drm_display_mode *mode;
>         unsigned pixel_clock = (timings->pixel_clock[0] |
> @@ -5057,6 +5093,7 @@ static struct drm_display_mode *drm_mode_displayid_detailed(struct drm_device *d
>         unsigned vsync_width = (timings->vsw[0] | timings->vsw[1] << 8) + 1;
>         bool hsync_positive = (timings->hsync[1] >> 7) & 0x1;
>         bool vsync_positive = (timings->vsync[1] >> 7) & 0x1;
> +
>         mode = drm_mode_create(dev);
>         if (!mode)
>                 return NULL;
> @@ -5086,9 +5123,10 @@ static struct drm_display_mode *drm_mode_displayid_detailed(struct drm_device *d
>  }
>
>  static int add_displayid_detailed_1_modes(struct drm_connector *connector,
> -                                         struct displayid_block *block)
> +                                         const struct displayid_block *block)
>  {
> -       struct displayid_detailed_timing_block *det = (struct displayid_detailed_timing_block *)block;
> +       const struct displayid_detailed_timing_block *det =
> +               (const struct displayid_detailed_timing_block *)block;
>         int i;
>         int num_timings;
>         struct drm_display_mode *newmode;
> @@ -5099,7 +5137,7 @@ static int add_displayid_detailed_1_modes(struct drm_connector *connector,
>
>         num_timings = block->num_bytes / 20;
>         for (i = 0; i < num_timings; i++) {
> -               struct displayid_detailed_timings_1 *timings = &det->timings[i];
> +               const struct displayid_detailed_timings_1 *timings = &det->timings[i];
>
>                 newmode = drm_mode_displayid_detailed(connector->dev, timings);
>                 if (!newmode)
> @@ -5112,13 +5150,13 @@ static int add_displayid_detailed_1_modes(struct drm_connector *connector,
>  }
>
>  static int add_displayid_detailed_modes(struct drm_connector *connector,
> -                                       struct edid *edid)
> +                                       const struct edid *edid)
>  {
> -       u8 *displayid;
> +       const u8 *displayid;
>         int ret;
>         int idx = 1;
>         int length = EDID_LENGTH;
> -       struct displayid_block *block;
> +       const struct displayid_block *block;
>         int num_modes = 0;
>
>         displayid = drm_find_displayid_extension(edid);
> @@ -5720,9 +5758,10 @@ drm_hdmi_vendor_infoframe_from_display_mode(struct hdmi_vendor_infoframe *frame,
>  EXPORT_SYMBOL(drm_hdmi_vendor_infoframe_from_display_mode);
>
>  static int drm_parse_tiled_block(struct drm_connector *connector,
> -                                struct displayid_block *block)
> +                                const struct displayid_block *block)
>  {
> -       struct displayid_tiled_block *tile = (struct displayid_tiled_block *)block;
> +       const struct displayid_tiled_block *tile =
> +               (const struct displayid_tiled_block *)block;
>         u16 w, h;
>         u8 tile_v_loc, tile_h_loc;
>         u8 num_v_tile, num_h_tile;
> @@ -5774,12 +5813,12 @@ static int drm_parse_tiled_block(struct drm_connector *connector,
>  }
>
>  static int drm_parse_display_id(struct drm_connector *connector,
> -                               u8 *displayid, int length,
> +                               const u8 *displayid, int length,
>                                 bool is_edid_extension)
>  {
>         /* if this is an EDID extension the first byte will be 0x70 */
>         int idx = 0;
> -       struct displayid_block *block;
> +       const struct displayid_block *block;
>         int ret;
>
>         if (is_edid_extension)
> @@ -5815,11 +5854,13 @@ static int drm_parse_display_id(struct drm_connector *connector,
>  }
>
>  static void drm_get_displayid(struct drm_connector *connector,
> -                             struct edid *edid)
> +                             const struct edid *edid)
>  {
> -       void *displayid = NULL;
> +       const void *displayid;
>         int ret;
> +
>         connector->has_tile = false;
> +
>         displayid = drm_find_displayid_extension(edid);
>         if (!displayid) {
>                 /* drop reference to any tile group we had */
> diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
> index 2113500b4075..c0f9ce3f4b24 100644
> --- a/include/drm/drm_connector.h
> +++ b/include/drm/drm_connector.h
> @@ -1580,9 +1580,9 @@ struct drm_tile_group {
>  };
>
>  struct drm_tile_group *drm_mode_create_tile_group(struct drm_device *dev,
> -                                                 char topology[8]);
> +                                                 const u8 topology[8]);
>  struct drm_tile_group *drm_mode_get_tile_group(struct drm_device *dev,
> -                                              char topology[8]);
> +                                              const u8 topology[8]);
>  void drm_mode_put_tile_group(struct drm_device *dev,
>                              struct drm_tile_group *tg);
>
> --
> 2.24.1
>
> _______________________________________________
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> dri-devel at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel


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