[PATCH] omapfb: dss: Fix max fclk divider for omap36xx

[Tomi Valkeinen]

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 at vger.kernel.org> #4.9+
>>> Signed-off-by: Adam Ford <aford173 at 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 at 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 at ti.com>
> Cc: Dave Airlie <airlied at gmail.com>
> Cc: Rob Clark <robdclark at gmail.com>
> Cc: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> Cc: Sam Ravnborg <sam at ravnborg.org>
> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie at samsung.com>
> Cc: Jason Yan <yanaijie at huawei.com>
> Cc: "Andrew F. Davis" <afd at ti.com>
> Cc: YueHaibing <yuehaibing at huawei.com>
> Cc: <stable at 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+.

  Tomi

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