[Intel-gfx] [PATCH 06/15] drm/i915/bios: rewrite sequence block parsing
Daniel Vetter
daniel at ffwll.ch
Tue Jan 5 06:12:00 PST 2016
On Mon, Dec 21, 2015 at 03:10:57PM +0200, Jani Nikula wrote:
> Make everything a bit more readable and clear.
>
> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
A real pain to check, but I think I convinced myself that this is
equivalent code.
Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> ---
> drivers/gpu/drm/i915/i915_drv.h | 2 +-
> drivers/gpu/drm/i915/intel_bios.c | 158 +++++++++++++-------------------------
> drivers/gpu/drm/i915/intel_bios.h | 4 +-
> 3 files changed, 57 insertions(+), 107 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 9b82c4532893..07c4fc539680 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1487,7 +1487,7 @@ struct intel_vbt_data {
> u8 seq_version;
> u32 size;
> u8 *data;
> - u8 *sequence[MIPI_SEQ_MAX];
> + const u8 *sequence[MIPI_SEQ_MAX];
> } dsi;
>
> int crt_ddc_pin;
> diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
> index 9511a5341562..d6eaf32f33e5 100644
> --- a/drivers/gpu/drm/i915/intel_bios.c
> +++ b/drivers/gpu/drm/i915/intel_bios.c
> @@ -697,73 +697,6 @@ parse_psr(struct drm_i915_private *dev_priv, const struct bdb_header *bdb)
> dev_priv->vbt.psr.tp2_tp3_wakeup_time = psr_table->tp2_tp3_wakeup_time;
> }
>
> -static u8 *goto_next_sequence(u8 *data, u16 *size)
> -{
> - u16 len;
> - int tmp = *size;
> -
> - if (--tmp < 0)
> - return NULL;
> -
> - /* goto first element */
> - data++;
> - while (1) {
> - switch (*data) {
> - case MIPI_SEQ_ELEM_SEND_PKT:
> - /*
> - * skip by this element payload size
> - * skip elem id, command flag and data type
> - */
> - tmp -= 5;
> - if (tmp < 0)
> - return NULL;
> -
> - data += 3;
> - len = *((u16 *)data);
> -
> - tmp -= len;
> - if (tmp < 0)
> - return NULL;
> -
> - /* skip by len */
> - data = data + 2 + len;
> - break;
> - case MIPI_SEQ_ELEM_DELAY:
> - /* skip by elem id, and delay is 4 bytes */
> - tmp -= 5;
> - if (tmp < 0)
> - return NULL;
> -
> - data += 5;
> - break;
> - case MIPI_SEQ_ELEM_GPIO:
> - tmp -= 3;
> - if (tmp < 0)
> - return NULL;
> -
> - data += 3;
> - break;
> - default:
> - DRM_ERROR("Unknown element\n");
> - return NULL;
> - }
> -
> - /* end of sequence ? */
> - if (*data == 0)
> - break;
> - }
> -
> - /* goto next sequence or end of block byte */
> - if (--tmp < 0)
> - return NULL;
> -
> - data++;
> -
> - /* update amount of data left for the sequence block to be parsed */
> - *size = tmp;
> - return data;
> -}
> -
> static void
> parse_mipi_config(struct drm_i915_private *dev_priv,
> const struct bdb_header *bdb)
> @@ -855,6 +788,39 @@ find_panel_sequence_block(const struct bdb_mipi_sequence *sequence,
> return NULL;
> }
>
> +static int goto_next_sequence(const u8 *data, int index, int total)
> +{
> + u16 len;
> +
> + /* Skip Sequence Byte. */
> + for (index = index + 1; index < total; index += len) {
> + u8 operation_byte = *(data + index);
> + index++;
> +
> + switch (operation_byte) {
> + case MIPI_SEQ_ELEM_END:
> + return index;
> + case MIPI_SEQ_ELEM_SEND_PKT:
> + if (index + 4 > total)
> + return 0;
> +
> + len = *((const u16 *)(data + index + 2)) + 4;
> + break;
> + case MIPI_SEQ_ELEM_DELAY:
> + len = 4;
> + break;
> + case MIPI_SEQ_ELEM_GPIO:
> + len = 2;
> + break;
> + default:
> + DRM_ERROR("Unknown operation byte\n");
> + return 0;
> + }
> + }
> +
> + return 0;
> +}
> +
> static void
> parse_mipi_sequence(struct drm_i915_private *dev_priv,
> const struct bdb_header *bdb)
> @@ -863,7 +829,7 @@ parse_mipi_sequence(struct drm_i915_private *dev_priv,
> const u8 *seq_data;
> u16 seq_size;
> u8 *data;
> - u16 block_size;
> + int index = 0;
>
> /* Only our generic panel driver uses the sequence block. */
> if (dev_priv->vbt.dsi.panel_id != MIPI_DSI_GENERIC_PANEL_ID)
> @@ -883,59 +849,43 @@ parse_mipi_sequence(struct drm_i915_private *dev_priv,
>
> DRM_DEBUG_DRIVER("Found MIPI sequence block\n");
>
> - block_size = get_blocksize(sequence);
> -
> - /*
> - * parse the sequence block for individual sequences
> - */
> - dev_priv->vbt.dsi.seq_version = sequence->version;
> -
> seq_data = find_panel_sequence_block(sequence, panel_type, &seq_size);
> if (!seq_data)
> return;
>
> - dev_priv->vbt.dsi.data = kmemdup(seq_data, seq_size, GFP_KERNEL);
> - if (!dev_priv->vbt.dsi.data)
> + data = kmemdup(seq_data, seq_size, GFP_KERNEL);
> + if (!data)
> return;
>
> - /*
> - * loop into the sequence data and split into multiple sequneces
> - * There are only 5 types of sequences as of now
> - */
> - data = dev_priv->vbt.dsi.data;
> - dev_priv->vbt.dsi.size = seq_size;
> + /* Parse the sequences, store pointers to each sequence. */
> + for (;;) {
> + u8 seq_id = *(data + index);
> + if (seq_id == MIPI_SEQ_END)
> + break;
>
> - /* two consecutive 0x00 indicate end of all sequences */
> - while (1) {
> - int seq_id = *data;
> - if (MIPI_SEQ_MAX > seq_id && seq_id > MIPI_SEQ_UNDEFINED) {
> - dev_priv->vbt.dsi.sequence[seq_id] = data;
> - DRM_DEBUG_DRIVER("Found mipi sequence - %d\n", seq_id);
> - } else {
> - DRM_ERROR("undefined sequence\n");
> + if (seq_id >= MIPI_SEQ_MAX) {
> + DRM_ERROR("Unknown sequence %u\n", seq_id);
> goto err;
> }
>
> - /* partial parsing to skip elements */
> - data = goto_next_sequence(data, &seq_size);
> + dev_priv->vbt.dsi.sequence[seq_id] = data + index;
>
> - if (data == NULL) {
> - DRM_ERROR("Sequence elements going beyond block itself. Sequence block parsing failed\n");
> + index = goto_next_sequence(data, index, seq_size);
> + if (!index) {
> + DRM_ERROR("Invalid sequence %u\n", seq_id);
> goto err;
> }
> -
> - if (*data == 0)
> - break; /* end of sequence reached */
> }
>
> - DRM_DEBUG_DRIVER("MIPI related vbt parsing complete\n");
> + dev_priv->vbt.dsi.data = data;
> + dev_priv->vbt.dsi.size = seq_size;
> + dev_priv->vbt.dsi.seq_version = sequence->version;
> +
> + DRM_DEBUG_DRIVER("MIPI related VBT parsing complete\n");
> return;
> -err:
> - kfree(dev_priv->vbt.dsi.data);
> - dev_priv->vbt.dsi.data = NULL;
>
> - /* error during parsing so set all pointers to null
> - * because of partial parsing */
> +err:
> + kfree(data);
> memset(dev_priv->vbt.dsi.sequence, 0, sizeof(dev_priv->vbt.dsi.sequence));
> }
>
> diff --git a/drivers/gpu/drm/i915/intel_bios.h b/drivers/gpu/drm/i915/intel_bios.h
> index 21c162e01189..4e87df16e7b3 100644
> --- a/drivers/gpu/drm/i915/intel_bios.h
> +++ b/drivers/gpu/drm/i915/intel_bios.h
> @@ -954,7 +954,7 @@ struct bdb_mipi_sequence {
>
> /* MIPI Sequnece Block definitions */
> enum mipi_seq {
> - MIPI_SEQ_UNDEFINED = 0,
> + MIPI_SEQ_END = 0,
> MIPI_SEQ_ASSERT_RESET,
> MIPI_SEQ_INIT_OTP,
> MIPI_SEQ_DISPLAY_ON,
> @@ -964,7 +964,7 @@ enum mipi_seq {
> };
>
> enum mipi_seq_element {
> - MIPI_SEQ_ELEM_UNDEFINED = 0,
> + MIPI_SEQ_ELEM_END = 0,
> MIPI_SEQ_ELEM_SEND_PKT,
> MIPI_SEQ_ELEM_DELAY,
> MIPI_SEQ_ELEM_GPIO,
> --
> 2.1.4
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
More information about the Intel-gfx
mailing list