| Message ID | 20220824130034.196041-3-tomi.valkeinen@ideasonboard.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Kieran Bingham |
| Headers | show |
| Series | drm/bridge: ti-sn65dsi86: Basic DP support | expand |
Hi Tomi, Thank you for the patch. On Wed, Aug 24, 2022 at 04:00:32PM +0300, Tomi Valkeinen wrote: > From: Tomi Valkeinen <tomi.valkeinen+renesas@ideasonboard.com> > > The blanking related registers are 8 bits, so reject any modes > with larger blanking periods. > > Signed-off-by: Tomi Valkeinen <tomi.valkeinen+renesas@ideasonboard.com> > --- > drivers/gpu/drm/bridge/ti-sn65dsi86.c | 23 +++++++++++++++++++++++ > 1 file changed, 23 insertions(+) > > diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c > index ba84215c1511..f085a037ff5b 100644 > --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c > +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c > @@ -752,6 +752,29 @@ ti_sn_bridge_mode_valid(struct drm_bridge *bridge, > if (mode->clock > 594000) > return MODE_CLOCK_HIGH; > > + /* > + * The blanking related registers are 8 bits, so reject any modes s/blanking register/blanking-related/ > + * with larger blanking periods. > + */ > + > + if ((mode->hsync_start - mode->hdisplay) > 0xff) > + return MODE_HBLANK_WIDE; > + > + if ((mode->vsync_start - mode->vdisplay) > 0xff) > + return MODE_VBLANK_WIDE; > + > + if ((mode->hsync_end - mode->hsync_start) > 0xff) > + return MODE_HSYNC_WIDE; > + > + if ((mode->vsync_end - mode->vsync_start) > 0xff) > + return MODE_VSYNC_WIDE; > + > + if ((mode->htotal - mode->hsync_end) > 0xff) > + return MODE_HBLANK_WIDE; > + > + if ((mode->vtotal - mode->vsync_end) > 0xff) > + return MODE_VBLANK_WIDE; You could drop all inner parentheses. Up to you. Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > + > return MODE_OK; > } >
Hi, On Wed, Aug 24, 2022 at 6:00 AM Tomi Valkeinen <tomi.valkeinen@ideasonboard.com> wrote: > > From: Tomi Valkeinen <tomi.valkeinen+renesas@ideasonboard.com> > > The blanking related registers are 8 bits, so reject any modes > with larger blanking periods. > > Signed-off-by: Tomi Valkeinen <tomi.valkeinen+renesas@ideasonboard.com> > --- > drivers/gpu/drm/bridge/ti-sn65dsi86.c | 23 +++++++++++++++++++++++ > 1 file changed, 23 insertions(+) > > diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c > index ba84215c1511..f085a037ff5b 100644 > --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c > +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c > @@ -752,6 +752,29 @@ ti_sn_bridge_mode_valid(struct drm_bridge *bridge, > if (mode->clock > 594000) > return MODE_CLOCK_HIGH; > > + /* > + * The blanking related registers are 8 bits, so reject any modes > + * with larger blanking periods. > + */ > + > + if ((mode->hsync_start - mode->hdisplay) > 0xff) > + return MODE_HBLANK_WIDE; > + > + if ((mode->vsync_start - mode->vdisplay) > 0xff) > + return MODE_VBLANK_WIDE; > + > + if ((mode->hsync_end - mode->hsync_start) > 0xff) > + return MODE_HSYNC_WIDE; Please double-check your patch. Reading through ti_sn_bridge_set_video_timings(), I see "mode->hsync_end - mode->hsync_start" is allowed to be up to 0x7fff. The datasheet seems to confirm. If I got that right it means you're rejecting valid modes. I didn't validate any of your other checks, but at least that one seems wrong. SInce this already had a Reviewed-by tag, being explicit: Naked-by: Douglas Anderson <dianders@chromium.org>
Hi Doug, On 29/08/2022 20:23, Doug Anderson wrote: > Hi, > > On Wed, Aug 24, 2022 at 6:00 AM Tomi Valkeinen > <tomi.valkeinen@ideasonboard.com> wrote: >> >> From: Tomi Valkeinen <tomi.valkeinen+renesas@ideasonboard.com> >> >> The blanking related registers are 8 bits, so reject any modes >> with larger blanking periods. >> >> Signed-off-by: Tomi Valkeinen <tomi.valkeinen+renesas@ideasonboard.com> >> --- >> drivers/gpu/drm/bridge/ti-sn65dsi86.c | 23 +++++++++++++++++++++++ >> 1 file changed, 23 insertions(+) >> >> diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c >> index ba84215c1511..f085a037ff5b 100644 >> --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c >> +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c >> @@ -752,6 +752,29 @@ ti_sn_bridge_mode_valid(struct drm_bridge *bridge, >> if (mode->clock > 594000) >> return MODE_CLOCK_HIGH; >> >> + /* >> + * The blanking related registers are 8 bits, so reject any modes >> + * with larger blanking periods. >> + */ >> + >> + if ((mode->hsync_start - mode->hdisplay) > 0xff) >> + return MODE_HBLANK_WIDE; >> + >> + if ((mode->vsync_start - mode->vdisplay) > 0xff) >> + return MODE_VBLANK_WIDE; >> + >> + if ((mode->hsync_end - mode->hsync_start) > 0xff) >> + return MODE_HSYNC_WIDE; > > Please double-check your patch. Reading through > ti_sn_bridge_set_video_timings(), I see "mode->hsync_end - > mode->hsync_start" is allowed to be up to 0x7fff. The datasheet seems > to confirm. If I got that right it means you're rejecting valid modes. > > I didn't validate any of your other checks, but at least that one seems wrong. Indeed, I misread the spec. The pulse width registers are 15 bits. The front and back porch are 8 bits. Thanks! Tomi
diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c index ba84215c1511..f085a037ff5b 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -752,6 +752,29 @@ ti_sn_bridge_mode_valid(struct drm_bridge *bridge, if (mode->clock > 594000) return MODE_CLOCK_HIGH; + /* + * The blanking related registers are 8 bits, so reject any modes + * with larger blanking periods. + */ + + if ((mode->hsync_start - mode->hdisplay) > 0xff) + return MODE_HBLANK_WIDE; + + if ((mode->vsync_start - mode->vdisplay) > 0xff) + return MODE_VBLANK_WIDE; + + if ((mode->hsync_end - mode->hsync_start) > 0xff) + return MODE_HSYNC_WIDE; + + if ((mode->vsync_end - mode->vsync_start) > 0xff) + return MODE_VSYNC_WIDE; + + if ((mode->htotal - mode->hsync_end) > 0xff) + return MODE_HBLANK_WIDE; + + if ((mode->vtotal - mode->vsync_end) > 0xff) + return MODE_VBLANK_WIDE; + return MODE_OK; }