Re: [PATCH v11 08/16] drm/mediatek: De-commonize disp_aal/disp_gamma gamma_set functions

[AngeloGioacchino Del Regno]

Il 13/10/23 06:07, CK Hu (胡俊光) ha scritto:
> Hi, Angelo:
>
> On Thu, 2023-10-12 at 11:57 +0200, AngeloGioacchino Del Regno wrote:
> > In preparation for adding a 12-bits gamma support for the DISP_GAMMA
> > IP, remove the mtk_gamma_set_common() function and move the relevant
> > bits in mtk_gamma_set() for DISP_GAMMA and mtk_aal_gamma_set() for
> > DISP_AAL: since the latter has no more support for gamma manipulation
> > (being moved to a different IP) in newer revisions, those functions
> > are about to diverge and it makes no sense to keep a common one (with
> > all the complications of passing common data and making exclusions
> > for device driver data) for just a few bits.
> >
> > This commit brings no functional changes.
>
> Reviewed-by: CK Hu <ck.hu@xxxxxxxxxxxx>
>
> > Signed-off-by: AngeloGioacchino Del Regno <
> > angelogioacchino.delregno@xxxxxxxxxxxxx>

..snip..

> > diff --git a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> > b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> > index 81c04518a5eb..0929f8830d6d 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> > @@ -69,41 +69,28 @@ unsigned int mtk_gamma_get_lut_size(struct device
> > *dev)
> >   	return 0;
> >   }
> >   
> > -void mtk_gamma_set_common(struct device *dev, void __iomem *regs,
> > struct drm_crtc_state *state)
> > +void mtk_gamma_set(struct device *dev, struct drm_crtc_state *state)
> >   {

..snip..

> >   
> > -	cfg_val = readl(regs + DISP_GAMMA_CFG);
> > +	cfg_val = readl(gamma->regs + DISP_GAMMA_CFG);
> >   
> >   	/* Enable the gamma table */
> >   	cfg_val |= FIELD_PREP(GAMMA_LUT_EN, 1);
> >   
> > -	writel(cfg_val, regs + DISP_GAMMA_CFG);
> > -}
> > -
> > -void mtk_gamma_set(struct device *dev, struct drm_crtc_state *state)
> > -{
> > -	struct mtk_disp_gamma *gamma = dev_get_drvdata(dev);
> > -
> > -	mtk_gamma_set_common(dev, gamma->regs, state);
> > +	writel(cfg_val, gamma->regs + DISP_GAMMA_CFG);

Hello CK,

something went wrong while you applied this patch: this writel became a readl,
breaking mtk_disp_gamma entirely. Please check:

https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/drivers/gpu/drm/mediatek/mtk_disp_gamma.c?h=next-20231025&id=a6b39cd248f3321dbf066f95f95a9841f891229e

Thanks,
Angelo