[PATCH 1/3] drm/omap: Pass along the format info from .fb_create() to drm_helper_mode_fill_fb_struct()
Imre Deak
imre.deak at intel.com
Tue Aug 5 18:04:16 UTC 2025
On Tue, Aug 05, 2025 at 07:56:50PM +0300, Tomi Valkeinen wrote:
> Hi,
>
> On 05/08/2025 19:22, Imre Deak wrote:
> > On Tue, Aug 05, 2025 at 06:43:04PM +0300, Tomi Valkeinen wrote:
> >> Hi,
> >>
> >> On 05/08/2025 17:49, Imre Deak wrote:
> >>> Hi Tomi,
> >>>
> >>> On Tue, Aug 05, 2025 at 02:53:36PM +0300, Tomi Valkeinen wrote:
> >>>> Hi Imre,
> >>>>
> >>>> On 28/07/2025 13:16, Imre Deak wrote:
> >>>>> Plumb the format info from .fb_create() all the way to
> >>>>> drm_helper_mode_fill_fb_struct() to avoid the redundant
> >>>>> lookup.
> >>>>>
> >>>>> For the fbdev case a manual drm_get_format_info() lookup
> >>>>> is needed.
> >>>>>
> >>>>> The patch is based on the driver parts of the patchset at Link:
> >>>>> below, which missed converting the omap driver.
> >>>>>
> >>>>> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> >>>>> Cc: Tomi Valkeinen <tomi.valkeinen at ideasonboard.com>
> >>>>> Cc: Thomas Zimmermann <tzimmermann at suse.de>
> >>>>> Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> >>>>> Cc: Maxime Ripard <mripard at kernel.org>
> >>>>> Fixes: 41ab92d35ccd ("drm: Make passing of format info to drm_helper_mode_fill_fb_struct() mandatory")
> >>>>> Reported-by: Mark Brown <broonie at kernel.org>
> >>>>> Closes: https://lore.kernel.org/all/98b3a62c-91ff-4f91-a58b-e1265f84180b@sirena.org.uk
> >>>>> Link: https://lore.kernel.org/all/20250701090722.13645-1-ville.syrjala@linux.intel.com
> >>>>> Signed-off-by: Imre Deak <imre.deak at intel.com>
> >>>>> ---
> >>>>> drivers/gpu/drm/omapdrm/omap_fb.c | 23 ++++++++++-------------
> >>>>> drivers/gpu/drm/omapdrm/omap_fb.h | 2 ++
> >>>>> drivers/gpu/drm/omapdrm/omap_fbdev.c | 5 ++++-
> >>>>> 3 files changed, 16 insertions(+), 14 deletions(-)
> >>>>>
> >>>>> diff --git a/drivers/gpu/drm/omapdrm/omap_fb.c b/drivers/gpu/drm/omapdrm/omap_fb.c
> >>>>> index 30c81e2e5d6b3..bb3105556f193 100644
> >>>>> --- a/drivers/gpu/drm/omapdrm/omap_fb.c
> >>>>> +++ b/drivers/gpu/drm/omapdrm/omap_fb.c
> >>>>> @@ -351,7 +351,7 @@ struct drm_framebuffer *omap_framebuffer_create(struct drm_device *dev,
> >>>>> }
> >>>>> }
> >>>>>
> >>>>> - fb = omap_framebuffer_init(dev, mode_cmd, bos);
> >>>>> + fb = omap_framebuffer_init(dev, info, mode_cmd, bos);
> >>>>> if (IS_ERR(fb))
> >>>>> goto error;
> >>>>>
> >>>>> @@ -365,9 +365,9 @@ struct drm_framebuffer *omap_framebuffer_create(struct drm_device *dev,
> >>>>> }
> >>>>>
> >>>>> struct drm_framebuffer *omap_framebuffer_init(struct drm_device *dev,
> >>>>> + const struct drm_format_info *info,
> >>>>> const struct drm_mode_fb_cmd2 *mode_cmd, struct drm_gem_object **bos)
> >>>>> {
> >>>>> - const struct drm_format_info *format = NULL;
> >>>>> struct omap_framebuffer *omap_fb = NULL;
> >>>>> struct drm_framebuffer *fb = NULL;
> >>>>> unsigned int pitch = mode_cmd->pitches[0];
> >>>>> @@ -377,15 +377,12 @@ struct drm_framebuffer *omap_framebuffer_init(struct drm_device *dev,
> >>>>> dev, mode_cmd, mode_cmd->width, mode_cmd->height,
> >>>>> (char *)&mode_cmd->pixel_format);
> >>>>>
> >>>>> - format = drm_get_format_info(dev, mode_cmd->pixel_format,
> >>>>> - mode_cmd->modifier[0]);
> >>>>> -
> >>>>> for (i = 0; i < ARRAY_SIZE(formats); i++) {
> >>>>> if (formats[i] == mode_cmd->pixel_format)
> >>>>> break;
> >>>>> }
> >>>>>
> >>>>> - if (!format || i == ARRAY_SIZE(formats)) {
> >>>>> + if (i == ARRAY_SIZE(formats)) {
> >>>>> dev_dbg(dev->dev, "unsupported pixel format: %4.4s\n",
> >>>>> (char *)&mode_cmd->pixel_format);
> >>>>> ret = -EINVAL;
> >>>>> @@ -399,7 +396,7 @@ struct drm_framebuffer *omap_framebuffer_init(struct drm_device *dev,
> >>>>> }
> >>>>>
> >>>>> fb = &omap_fb->base;
> >>>>> - omap_fb->format = format;
> >>>>> + omap_fb->format = info;
> >>>>> mutex_init(&omap_fb->lock);
> >>>>>
> >>>>> /*
> >>>>> @@ -407,23 +404,23 @@ struct drm_framebuffer *omap_framebuffer_init(struct drm_device *dev,
> >>>>> * that the two planes of multiplane formats need the same number of
> >>>>> * bytes per pixel.
> >>>>> */
> >>>>> - if (format->num_planes == 2 && pitch != mode_cmd->pitches[1]) {
> >>>>> + if (info->num_planes == 2 && pitch != mode_cmd->pitches[1]) {
> >>>>> dev_dbg(dev->dev, "pitches differ between planes 0 and 1\n");
> >>>>> ret = -EINVAL;
> >>>>> goto fail;
> >>>>> }
> >>>>>
> >>>>> - if (pitch % format->cpp[0]) {
> >>>>> + if (pitch % info->cpp[0]) {
> >>>>> dev_dbg(dev->dev,
> >>>>> "buffer pitch (%u bytes) is not a multiple of pixel size (%u bytes)\n",
> >>>>> - pitch, format->cpp[0]);
> >>>>> + pitch, info->cpp[0]);
> >>>>> ret = -EINVAL;
> >>>>> goto fail;
> >>>>> }
> >>>>>
> >>>>> - for (i = 0; i < format->num_planes; i++) {
> >>>>> + for (i = 0; i < info->num_planes; i++) {
> >>>>> struct plane *plane = &omap_fb->planes[i];
> >>>>> - unsigned int vsub = i == 0 ? 1 : format->vsub;
> >>>>> + unsigned int vsub = i == 0 ? 1 : info->vsub;
> >>>>> unsigned int size;
> >>>>>
> >>>>> size = pitch * mode_cmd->height / vsub;
> >>>>> @@ -440,7 +437,7 @@ struct drm_framebuffer *omap_framebuffer_init(struct drm_device *dev,
> >>>>> plane->dma_addr = 0;
> >>>>> }
> >>>>>
> >>>>> - drm_helper_mode_fill_fb_struct(dev, fb, NULL, mode_cmd);
> >>>>> + drm_helper_mode_fill_fb_struct(dev, fb, info, mode_cmd);
> >>>>
> >>>> Isn't the fix really a one-liner, just passing "format" here instead of
> >>>> NULL?
> >>>
> >>> That would fix the issue of fb->format being initialized to NULL yes.
> >>>
> >>> However, I think the change should be in sync with the conversion of the
> >>> rest of the drivers in patchset [1]. IOW, what this patch is meant to
> >>> fix is that [1] missed converting the OMAP driver similarly to the other
> >>> drivers.
> >>>
> >>> I think the change is equivalent to the above one-liner you suggest with
> >>> the following differences:
> >>>
> >>> - omap_framebuffer_init() uses the drm_format_info passed down from either
> >>> drm_internal_framebuffer_create(), or omap_fbdev_driver_fbdev_probe().
> >>> In both cases the passed down format info matches what
> >>> omap_framebuffer_init() would look up again.
> >>>
> >>> - Skip the format == NULL check. format can't be NULL in any case, since
> >>> that would have emitted a WARN already in drm_get_format_info() ->
> >>> drm_format_info().
> >>>
> >>> [1] https://lore.kernel.org/all/20250701090722.13645-1-ville.syrjala@linux.intel.com
> >>
> >> Yep, I have no issue with the patch as such. But if it's a fix, going
> >> into an rc, I think it's better if it's as small as possible, and do the
> >> cleanups/refactorings as a non-fix later.
> >>
> >> The patch description here sounds more like it's just refactoring the
> >> code a bit, but if I understand correctly, it's fixing an issue that
> >> cause a WARN?
> >
> > Yes, the patch description should've mentioned that it fixes the
> > !fb->format WARN in drm_framebuffer_init() and the resulting failure to
> > create the framebuffer for fbdev and other FB users. I will add this.
> >
> >> So... Either we could 1) split the patch, have the WARN fix as a fix
> >> patch to the current rc, and the rest later in the next merge window, or
> >> 2) if you want to keep this as a single patch, I think it makes sense to
> >> change the subject and description to highlight the fix aspect.
> >
> > Yes, the patch should go to 6.17-rc1, but I would prefer 2) above, since
> > patchset [1] requiring it was also added in the same -rc1 and this patch
> > has been also tested at least by the bug reporter.
> >
> >> I think my comments apply to all patches in this series, as they're
> >> essentially doing the same thing...
> >
> > I can also amend the commit log for the other patches according to the
> > above.
>
> Alright. In any case, I don't think any of my concerns are big, but I
> wouldn't mind a clarification in the description. If you'll be pushing
> all these together:
>
> Reviewed-by: Tomi Valkeinen <tomi.valkeinen at ideasonboard.com>
Thanks.
> If you want me to merge the omap one separately, just say so.
I sent now the updated [1], which can be merged to drm-misc-next-fixes,
but I'm not sure if there's still a pull request to v6.17-rc1 from that.
So waiting now a suggestion on that.
[1] https://lore.kernel.org/all/20250805175752.690504-1-imre.deak@intel.com
>
> Tomi
>
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