On Sun, Jul 07, 2019 at 06:14:50PM +0200, Thomas Zimmermann wrote:
> Hi
>
> Am 07.07.19 um 16:37 schrieb Noralf Trønnes:
> >
> >
> > Den 05.07.2019 11.26, skrev Thomas Zimmermann:
> >> Generic framebuffer emulation uses a shadow buffer for framebuffers with
> >> dirty() function. If drivers want to use the shadow FB without such a
> >> function, they can now set prefer_shadow or prefer_shadow_fbdev in their
> >> mode_config structures. The former flag is exported to userspace, the latter
> >> flag is fbdev-only.
> >>
> >> Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
> >> ---
> >> drivers/gpu/drm/drm_fb_helper.c | 19 ++++++++++++++-----
> >> include/drm/drm_mode_config.h | 5 +++++
> >> 2 files changed, 19 insertions(+), 5 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
> >> index 7ba6a0255821..56ef169e1814 100644
> >> --- a/drivers/gpu/drm/drm_fb_helper.c
> >> +++ b/drivers/gpu/drm/drm_fb_helper.c
> >> @@ -421,7 +421,9 @@ static void drm_fb_helper_dirty_work(struct work_struct *work)
> >> return;
> >> drm_fb_helper_dirty_blit_real(helper, &clip_copy);
> >> }
> >> - helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, &clip_copy, 1);
> >> + if (helper->fb->funcs->dirty)
> >> + helper->fb->funcs->dirty(helper->fb, NULL, 0, 0,
> >> + &clip_copy, 1);
> >>
> >> if (helper->buffer)
> >> drm_client_buffer_vunmap(helper->buffer);
> >> @@ -620,9 +622,6 @@ static void drm_fb_helper_dirty(struct fb_info *info, u32 x, u32 y,
> >> struct drm_clip_rect *clip = &helper->dirty_clip;
> >> unsigned long flags;
> >>
> >> - if (!helper->fb->funcs->dirty)
> >> - return;
> >
> > drm_fb_helper_dirty() is called unconditionally by
> > drm_fb_helper_sys_imageblit() et al, so we need check with
> > drm_fbdev_use_shadow_fb() here.
> >
> >> -
> >> spin_lock_irqsave(&helper->dirty_lock, flags);
> >> clip->x1 = min_t(u32, clip->x1, x);
> >> clip->y1 = min_t(u32, clip->y1, y);
> >> @@ -2166,6 +2165,16 @@ static struct fb_deferred_io drm_fbdev_defio = {
> >> .deferred_io = drm_fb_helper_deferred_io,
> >> };
> >>
> >> +static bool drm_fbdev_use_shadow_fb(struct drm_fb_helper *fb_helper)
> >> +{
> >> + struct drm_device *dev = fb_helper->dev;
> >> + struct drm_framebuffer *fb = fb_helper->fb;
> >> +
> >> + return dev->mode_config.prefer_shadow_fbdev |
> >> + dev->mode_config.prefer_shadow |
> >
> > Use logical OR here
> >
> >> + !!fb->funcs->dirty;
> >
> > and you can drop the the double NOT here.
> >
> >> +}
> >> +
> >> /**
> >> * drm_fb_helper_generic_probe - Generic fbdev emulation probe helper
> >> * @fb_helper: fbdev helper structure
> >> @@ -2213,7 +2222,7 @@ int drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper,
> >>
> >> drm_fb_helper_fill_info(fbi, fb_helper, sizes);
> >>
> >> - if (fb->funcs->dirty) {
> >> + if (drm_fbdev_use_shadow_fb(fb_helper)) {
> >> struct fb_ops *fbops;
> >> void *shadow;
> >>
> >> diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h
> >> index 759d462d028b..e1c751aca353 100644
> >> --- a/include/drm/drm_mode_config.h
> >> +++ b/include/drm/drm_mode_config.h
> >> @@ -347,6 +347,8 @@ struct drm_mode_config_funcs {
> >> * @output_poll_work: delayed work for polling in process context
> >> * @preferred_depth: preferred RBG pixel depth, used by fb helpers
> >> * @prefer_shadow: hint to userspace to prefer shadow-fb rendering
> >> + * @prefer_shadow_fbdev: hint to framebuffer emulation to prefer shadow-fb \
> >> + rendering
> >
> > It's preferred to have the doc together with the struct member.
>
> I just tried to follow the file's existing style, but OK, I don't mind.
If it annoys you too much, convert all the member docs in the header
comment into the inline style. That's what I usually do when the first
inline kerneldoc comment is warranted (like here), but not yet rolled out.
Or just mix&match if you feel like not doing that, we have lots of that
already :-)
-Daniel
>
> > it's less likely to be forgotten when things change. And we don't use
> > line cont. when the doc line is too long. Just continue on the next line
> > after an asterix.
> >
> >> * @cursor_width: hint to userspace for max cursor width
> >> * @cursor_height: hint to userspace for max cursor height
> >> * @helper_private: mid-layer private data
> >> @@ -852,6 +854,9 @@ struct drm_mode_config {
> >> /* dumb ioctl parameters */
> >> uint32_t preferred_depth, prefer_shadow;
> >>
> >> + /* fbdev parameters */
> >
> > No need for this comment.
> >
> > Doc can look like this, I've done s/framebuffer/fbdev/:
> > /**
> > * @prefer_shadow_fbdev:
> > *
> > * Hint to fbdev emulation to prefer shadow-fb rendering.
> > */
> >
> >> + uint32_t prefer_shadow_fbdev;
> >
> > Use bool here.
> >
> > With that:
> >
> > Reviewed-by: Noralf Trønnes <noralf@xxxxxxxxxxx>
> >
> > I have tested this on 2 drivers that use generic fbdev: vc4 (no shadow
> > buf) and mi0283qt which has a dirty callback.
> >
> > Tested-by: Noralf Trønnes <noralf@xxxxxxxxxxx>
>
> Thanks for reviewing and testing the patches.
>
> Best regards
> Thomas
>
> >
> >> +
> >> /**
> >> * @quirk_addfb_prefer_xbgr_30bpp:
> >> *
> >>
> > _______________________________________________
> > dri-devel mailing list
> > dri-devel@xxxxxxxxxxxxxxxxxxxxx
> > https://lists.freedesktop.org/mailman/listinfo/dri-devel
> >
>
> --
> Thomas Zimmermann
> Graphics Driver Developer
> SUSE Linux GmbH, Maxfeldstrasse 5, 90409 Nuernberg, Germany
> GF: Felix Imendörffer, Mary Higgins, Sri Rasiah
> HRB 21284 (AG Nürnberg)
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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