| Message ID | 20200630182636.439015-1-aford173@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | omapfb: dss: Fix max fclk divider for omap36xx | expand |
On Wed, Jul 08, 2020 at 06:37:51PM -0500, Adam Ford wrote: > On Mon, Jul 6, 2020 at 6:18 AM Adam Ford <aford173@gmail.com> wrote: > > > > On Mon, Jul 6, 2020 at 1:02 AM Tomi Valkeinen <tomi.valkeinen@ti.com> wrote: > > > > > > Hi, > > > > > > On 03/07/2020 22:36, Sam Ravnborg wrote: > > > > Hi Tomi. > > > > > > > > On Fri, Jul 03, 2020 at 10:17:29AM +0300, Tomi Valkeinen wrote: > > > >> On 30/06/2020 21:26, Adam Ford wrote: > > > >>> The drm/omap driver was fixed to correct an issue where using a > > > >>> divider of 32 breaks the DSS despite the TRM stating 32 is a valid > > > >>> number. Through experimentation, it appears that 31 works, and > > > >>> it is consistent with the value used by the drm/omap driver. > > > >>> > > > >>> This patch fixes the divider for fbdev driver instead of the drm. > > > >>> > > > >>> Fixes: f76ee892a99e ("omapfb: copy omapdss & displays for omapfb") > > > >>> > > > >>> Cc: <stable@vger.kernel.org> #4.9+ > > > >>> Signed-off-by: Adam Ford <aford173@gmail.com> > > > >>> --- > > > >>> Linux 4.4 will need a similar patch, but it doesn't apply cleanly. > > > >>> > > > >>> The DRM version of this same fix is: > > > >>> e2c4ed148cf3 ("drm/omap: fix max fclk divider for omap36xx") > > > >>> > > > >>> > > > >>> diff --git a/drivers/video/fbdev/omap2/omapfb/dss/dss.c b/drivers/video/fbdev/omap2/omapfb/dss/dss.c > > > >>> index 7252d22dd117..bfc5c4c5a26a 100644 > > > >>> --- a/drivers/video/fbdev/omap2/omapfb/dss/dss.c > > > >>> +++ b/drivers/video/fbdev/omap2/omapfb/dss/dss.c > > > >>> @@ -833,7 +833,7 @@ static const struct dss_features omap34xx_dss_feats = { > > > >>> }; > > > >>> static const struct dss_features omap3630_dss_feats = { > > > >>> - .fck_div_max = 32, > > > >>> + .fck_div_max = 31, > > > >>> .dss_fck_multiplier = 1, > > > >>> .parent_clk_name = "dpll4_ck", > > > >>> .dpi_select_source = &dss_dpi_select_source_omap2_omap3, > > > >>> > > > >> > > > >> Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ti.com> > > > > Will you apply to drm-misc? > > > > > > This is for fbdev, so I presume Bartlomiej will pick this one. > > > > > > > Note following output from "dim fixes": > > > > $ dim fixes f76ee892a99e > > > > Fixes: f76ee892a99e ("omapfb: copy omapdss & displays for omapfb") > > > > Cc: Tomi Valkeinen <tomi.valkeinen@ti.com> > > > > Cc: Dave Airlie <airlied@gmail.com> > > > > Cc: Rob Clark <robdclark@gmail.com> > > > > Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > > > > Cc: Sam Ravnborg <sam@ravnborg.org> > > > > Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> > > > > Cc: Jason Yan <yanaijie@huawei.com> > > > > Cc: "Andrew F. Davis" <afd@ti.com> > > > > Cc: YueHaibing <yuehaibing@huawei.com> > > > > Cc: <stable@vger.kernel.org> # v4.5+ > > > > > > > > Here it says the fix is valid from v4.5 onwards. > > > > > > Hmm... Adam, you marked the fix to apply to v4.9+, and then you said > > > v4.4 needs a new patch (that's before the big copy/rename). Did you > > > check the versions between 4.4 and 4.9? I would guess this one applies > > > to v4.5+. > > > > I only tried 4.9 because it's listed as an LTS kernel. The stuff > > between 4.4 and 4.9 were EOL, so I didn't go back further. The 4.5+ > > is probably more accurate. I would like to do the same thing for the > > 4.4 kernel, but I am not sure the proper way to do that. > > What is the correct protocol for patching 4.4? I'd like to do that, > but the patch would be unique to the 4.4. Should I just submit the > patch directly to stable and cc Tomi? Yes, and document the heck out of why this is a 4.4-only patch, and why we can't take whatever happened in newer kernels instead. thanks, greg k-h
diff --git a/drivers/video/fbdev/omap2/omapfb/dss/dss.c b/drivers/video/fbdev/omap2/omapfb/dss/dss.c index 7252d22dd117..bfc5c4c5a26a 100644 --- a/drivers/video/fbdev/omap2/omapfb/dss/dss.c +++ b/drivers/video/fbdev/omap2/omapfb/dss/dss.c @@ -833,7 +833,7 @@ static const struct dss_features omap34xx_dss_feats = { }; static const struct dss_features omap3630_dss_feats = { - .fck_div_max = 32, + .fck_div_max = 31, .dss_fck_multiplier = 1, .parent_clk_name = "dpll4_ck", .dpi_select_source = &dss_dpi_select_source_omap2_omap3,
The drm/omap driver was fixed to correct an issue where using a divider of 32 breaks the DSS despite the TRM stating 32 is a valid number. Through experimentation, it appears that 31 works, and it is consistent with the value used by the drm/omap driver. This patch fixes the divider for fbdev driver instead of the drm. Fixes: f76ee892a99e ("omapfb: copy omapdss & displays for omapfb") Cc: <stable@vger.kernel.org> #4.9+ Signed-off-by: Adam Ford <aford173@gmail.com> --- Linux 4.4 will need a similar patch, but it doesn't apply cleanly. The DRM version of this same fix is: e2c4ed148cf3 ("drm/omap: fix max fclk divider for omap36xx")