[Intel-gfx] [PATCH] drm/i915/dp: refactor aux_ch_name()

[Gustavo Sousa]

Quoting Jani Nikula (2023-09-22 07:56:45-03:00)
>Convert aux_ch_name() to a helper that prints a string to a caller
>provided buffer, and use it to get more consistent aux channel
>debugs. Now that all users of aux_ch_name() are in intel_dp_aux.c, we
>can make it static too.
>
>Signed-off-by: Jani Nikula <jani.nikula at intel.com>

Reviewed-by: Gustavo Sousa <gustavo.sousa at intel.com>

>---
> drivers/gpu/drm/i915/display/intel_display.h |  2 -
> drivers/gpu/drm/i915/display/intel_dp_aux.c  | 41 ++++++++++++--------
> 2 files changed, 25 insertions(+), 18 deletions(-)
>
>diff --git a/drivers/gpu/drm/i915/display/intel_display.h b/drivers/gpu/drm/i915/display/intel_display.h
>index 49ac8473b988..9f252d1f03a7 100644
>--- a/drivers/gpu/drm/i915/display/intel_display.h
>+++ b/drivers/gpu/drm/i915/display/intel_display.h
>@@ -190,8 +190,6 @@ enum aux_ch {
>         AUX_CH_E_XELPD,
> };
> 
>-#define aux_ch_name(a) ((a) + 'A')
>-
> enum phy {
>         PHY_NONE = -1,
> 
>diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux.c b/drivers/gpu/drm/i915/display/intel_dp_aux.c
>index b90cad7f567b..4431b6290c4c 100644
>--- a/drivers/gpu/drm/i915/display/intel_dp_aux.c
>+++ b/drivers/gpu/drm/i915/display/intel_dp_aux.c
>@@ -14,6 +14,21 @@
> #include "intel_pps.h"
> #include "intel_tc.h"
> 
>+#define AUX_CH_NAME_BUFSIZE        6
>+
>+static const char *aux_ch_name(struct drm_i915_private *i915,
>+                               char *buf, int size, enum aux_ch aux_ch)
>+{
>+        if (DISPLAY_VER(i915) >= 13 && aux_ch >= AUX_CH_D_XELPD)
>+                snprintf(buf, size, "%c", 'A' + aux_ch - AUX_CH_D_XELPD + AUX_CH_D);
>+        else if (DISPLAY_VER(i915) >= 12 && aux_ch >= AUX_CH_USBC1)
>+                snprintf(buf, size, "USBC%c", '1' + aux_ch - AUX_CH_USBC1);
>+        else
>+                snprintf(buf, size, "%c", 'A' + aux_ch);
>+
>+        return buf;
>+}
>+
> u32 intel_dp_aux_pack(const u8 *src, int src_bytes)
> {
>         int i;
>@@ -728,6 +743,7 @@ void intel_dp_aux_init(struct intel_dp *intel_dp)
>         struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
>         struct intel_encoder *encoder = &dig_port->base;
>         enum aux_ch aux_ch = dig_port->aux_ch;
>+        char buf[AUX_CH_NAME_BUFSIZE];
> 
>         if (DISPLAY_VER(dev_priv) >= 14) {
>                 intel_dp->aux_ch_ctl_reg = xelpdp_aux_ctl_reg;
>@@ -764,18 +780,9 @@ void intel_dp_aux_init(struct intel_dp *intel_dp)
>         drm_dp_aux_init(&intel_dp->aux);
> 
>         /* Failure to allocate our preferred name is not critical */
>-        if (DISPLAY_VER(dev_priv) >= 13 && aux_ch >= AUX_CH_D_XELPD)
>-                intel_dp->aux.name = kasprintf(GFP_KERNEL, "AUX %c/%s",
>-                                               aux_ch_name(aux_ch - AUX_CH_D_XELPD + AUX_CH_D),
>-                                               encoder->base.name);
>-        else if (DISPLAY_VER(dev_priv) >= 12 && aux_ch >= AUX_CH_USBC1)
>-                intel_dp->aux.name = kasprintf(GFP_KERNEL, "AUX USBC%c/%s",
>-                                               aux_ch - AUX_CH_USBC1 + '1',
>-                                               encoder->base.name);
>-        else
>-                intel_dp->aux.name = kasprintf(GFP_KERNEL, "AUX %c/%s",
>-                                               aux_ch_name(aux_ch),
>-                                               encoder->base.name);
>+        intel_dp->aux.name = kasprintf(GFP_KERNEL, "AUX %s/%s",
>+                                       aux_ch_name(dev_priv, buf, sizeof(buf), aux_ch),
>+                                       encoder->base.name);
> 
>         intel_dp->aux.transfer = intel_dp_aux_transfer;
>         cpu_latency_qos_add_request(&intel_dp->pm_qos, PM_QOS_DEFAULT_VALUE);
>@@ -819,6 +826,7 @@ enum aux_ch intel_dp_aux_ch(struct intel_encoder *encoder)
>         struct intel_encoder *other;
>         const char *source;
>         enum aux_ch aux_ch;
>+        char buf[AUX_CH_NAME_BUFSIZE];
> 
>         aux_ch = intel_bios_dp_aux_ch(encoder->devdata);
>         source = "VBT";
>@@ -836,16 +844,17 @@ enum aux_ch intel_dp_aux_ch(struct intel_encoder *encoder)
>         other = get_encoder_by_aux_ch(encoder, aux_ch);
>         if (other) {
>                 drm_dbg_kms(&i915->drm,
>-                            "[ENCODER:%d:%s] AUX CH %c already claimed by [ENCODER:%d:%s]\n",
>-                            encoder->base.base.id, encoder->base.name, aux_ch_name(aux_ch),
>+                            "[ENCODER:%d:%s] AUX CH %s already claimed by [ENCODER:%d:%s]\n",
>+                            encoder->base.base.id, encoder->base.name,
>+                            aux_ch_name(i915, buf, sizeof(buf), aux_ch),
>                             other->base.base.id, other->base.name);
>                 return AUX_CH_NONE;
>         }
> 
>         drm_dbg_kms(&i915->drm,
>-                    "[ENCODER:%d:%s] Using AUX CH %c (%s)\n",
>+                    "[ENCODER:%d:%s] Using AUX CH %s (%s)\n",
>                     encoder->base.base.id, encoder->base.name,
>-                    aux_ch_name(aux_ch), source);
>+                    aux_ch_name(i915, buf, sizeof(buf), aux_ch), source);
> 
>         return aux_ch;
> }
>-- 
>2.39.2
>