On Tue, 24 Dec 2024, Gustavo Sousa <gustavo.sousa@xxxxxxxxx> wrote:
> Quoting Ville Syrjala (2024-12-19 10:08:25-03:00)
>>From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
>>
>>Include the standard "[CRTC:...]" information in the scaler debugs
>>to make life easier.
>
> Drive-by comment (and going a bit off-topic):
>
> $ git grep '\[[A-Z]\+:%d:%s]' -- drivers/gpu/drm | wc -l
> 600
>
> Has someone already considered creating DRM_*_FMT and DRM_*_ARG() for
> those? E.g. DRM_CRTC_FMT and CRM_CRTC_ARG(crtc->base), which, IMO, would
> be easier to use and arguably more concise.
Personally, I'm not in favour. I dislike having to concatenate the
string constants all over the place.
> I tried doing a quick search on lore.kernel.org/dri-devel, but I'm not
> sure what would be good search terms to find previous attempts to see
> possible arguments against it.
We've gone through this a number of times, and some of the other options
are:
- Add allocated debug string to the objects, e.g. crtc->debug or
crtc->id and print it with %s. It also works when you want to print
the info of e.g. both the connector and the encoder.
- Add function pointers for debug logging in the drm objects, and have
the drm_dbg* family of functions use them based on the type passed to
it with generics. You'd do drm_dbg_kms(connector, "foo\n"); and that
would add the [CONNECTOR:...] prefix. Falls short when you want to
print the info of multiple objects.
- Object specific debug logging macros. connector_dbg() etc. I'm
strongly against the proliferation of logging macros. All the variants
(like once, ratelimited, etc.) get multiplied by the number of object
types. (Yes, I also dislike the gt/guc macros, but I digress.) And
this also doesn't solve the logging of multiple objects at once.
- Add printk format specifiers. There's apparently no way to do this in
a human readable way, as anything nice throws off compiler printf
format checks. So you end up with stuff like %pXYZ where the XYZ are
meaningless magic letters. And they'd need to be implemented in kernel
core.
BR,
Jani.
>
> --
> Gustavo Sousa
>
>>
>>Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
>>---
>> drivers/gpu/drm/i915/display/skl_scaler.c | 25 +++++++++++++++--------
>> 1 file changed, 16 insertions(+), 9 deletions(-)
>>
>>diff --git a/drivers/gpu/drm/i915/display/skl_scaler.c b/drivers/gpu/drm/i915/display/skl_scaler.c
>>index cbc71e44fcbb..f6d76ef1a854 100644
>>--- a/drivers/gpu/drm/i915/display/skl_scaler.c
>>+++ b/drivers/gpu/drm/i915/display/skl_scaler.c
>>@@ -166,7 +166,8 @@ skl_update_scaler(struct intel_crtc_state *crtc_state, bool force_detach,
>> if (DISPLAY_VER(display) >= 9 && crtc_state->hw.enable &&
>> need_scaler && adjusted_mode->flags & DRM_MODE_FLAG_INTERLACE) {
>> drm_dbg_kms(display->drm,
>>- "Pipe/Plane scaling not supported with IF-ID mode\n");
>>+ "[CRTC:%d:%s] scaling not supported with IF-ID mode\n",
>>+ crtc->base.base.id, crtc->base.name);
>> return -EINVAL;
>> }
>>
>>@@ -186,8 +187,9 @@ skl_update_scaler(struct intel_crtc_state *crtc_state, bool force_detach,
>> scaler_state->scalers[*scaler_id].in_use = false;
>>
>> drm_dbg_kms(display->drm,
>>- "scaler_user index %u.%u: "
>>+ "[CRTC:%d:%s] scaler_user index %u.%u: "
>> "Staged freeing scaler id %d scaler_users = 0x%x\n",
>>+ crtc->base.base.id, crtc->base.name,
>> crtc->pipe, scaler_user, *scaler_id,
>> scaler_state->scaler_users);
>> *scaler_id = -1;
>>@@ -207,8 +209,9 @@ skl_update_scaler(struct intel_crtc_state *crtc_state, bool force_detach,
>> src_w > max_src_w || src_h > max_src_h ||
>> dst_w > max_dst_w || dst_h > max_dst_h) {
>> drm_dbg_kms(display->drm,
>>- "scaler_user index %u.%u: src %ux%u dst %ux%u "
>>+ "[CRTC:%d:%s] scaler_user index %u.%u: src %ux%u dst %ux%u "
>> "size is out of scaler range\n",
>>+ crtc->base.base.id, crtc->base.name,
>> crtc->pipe, scaler_user, src_w, src_h,
>> dst_w, dst_h);
>> return -EINVAL;
>>@@ -224,16 +227,18 @@ skl_update_scaler(struct intel_crtc_state *crtc_state, bool force_detach,
>> */
>> if (pipe_src_w > max_dst_w || pipe_src_h > max_dst_h) {
>> drm_dbg_kms(display->drm,
>>- "scaler_user index %u.%u: pipe src size %ux%u "
>>+ "[CRTC:%d:%s] scaler_user index %u.%u: pipe src size %ux%u "
>> "is out of scaler range\n",
>>+ crtc->base.base.id, crtc->base.name,
>> crtc->pipe, scaler_user, pipe_src_w, pipe_src_h);
>> return -EINVAL;
>> }
>>
>> /* mark this plane as a scaler user in crtc_state */
>> scaler_state->scaler_users |= (1 << scaler_user);
>>- drm_dbg_kms(display->drm, "scaler_user index %u.%u: "
>>+ drm_dbg_kms(display->drm, "[CRTC:%d:%s] scaler_user index %u.%u: "
>> "staged scaling request for %ux%u->%ux%u scaler_users = 0x%x\n",
>>+ crtc->base.base.id, crtc->base.name,
>> crtc->pipe, scaler_user, src_w, src_h, dst_w, dst_h,
>> scaler_state->scaler_users);
>>
>>@@ -421,8 +426,8 @@ static int intel_atomic_setup_scaler(struct intel_crtc_scaler_state *scaler_stat
>>
>> if (hscale < 0 || vscale < 0) {
>> drm_dbg_kms(display->drm,
>>- "Scaler %d doesn't support required plane scaling\n",
>>- *scaler_id);
>>+ "[CRTC:%d:%s] scaler %d doesn't support required plane scaling\n",
>>+ crtc->base.base.id, crtc->base.name, *scaler_id);
>> drm_rect_debug_print("src: ", src, true);
>> drm_rect_debug_print("dst: ", dst, false);
>>
>>@@ -430,7 +435,8 @@ static int intel_atomic_setup_scaler(struct intel_crtc_scaler_state *scaler_stat
>> }
>> }
>>
>>- drm_dbg_kms(display->drm, "Attached scaler id %u.%u to %s:%d\n",
>>+ drm_dbg_kms(display->drm, "[CRTC:%d:%s] attached scaler id %u.%u to %s:%d\n",
>>+ crtc->base.base.id, crtc->base.name,
>> crtc->pipe, *scaler_id, name, idx);
>> scaler_state->scalers[*scaler_id].mode = mode;
>>
>>@@ -530,7 +536,8 @@ int intel_atomic_setup_scalers(struct intel_atomic_state *state,
>> /* fail if required scalers > available scalers */
>> if (num_scalers_need > crtc->num_scalers) {
>> drm_dbg_kms(display->drm,
>>- "Too many scaling requests %d > %d\n",
>>+ "[CRTC:%d:%s] too many scaling requests %d > %d\n",
>>+ crtc->base.base.id, crtc->base.name,
>> num_scalers_need, crtc->num_scalers);
>> return -EINVAL;
>> }
>>--
>>2.45.2
>>
--
Jani Nikula, Intel
