Messages in this thread | | | Subject | Re: [EXT] Re: [v1] drm/arm/mali-dp: Disable checking for required pixel clock rate | From | Robin Murphy <> | Date | Thu, 16 May 2019 11:45:16 +0100 |
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On 16/05/2019 10:42, Wen He wrote: > > >> -----Original Message----- >> From: Robin Murphy [mailto:robin.murphy@arm.com] >> Sent: 2019年5月16日 1:14 >> To: Wen He <wen.he_1@nxp.com>; dri-devel@lists.freedesktop.org; >> linux-kernel@vger.kernel.org; liviu.dudau@arm.com >> Cc: Leo Li <leoyang.li@nxp.com> >> Subject: [EXT] Re: [v1] drm/arm/mali-dp: Disable checking for required pixel >> clock rate >> >> Caution: EXT Email >> >> On 15/05/2019 03:42, Wen He wrote: >>> Disable checking for required pixel clock rate if ARCH_LAYERSCPAE is >>> enable. >>> >>> Signed-off-by: Alison Wang <alison.wang@nxp.com> >>> Signed-off-by: Wen He <wen.he_1@nxp.com> >>> --- >>> change in description: >>> - This check that only supported one pixel clock required clock rate >>> compare with dts node value. but we have supports 4 pixel clock >>> for ls1028a board. >>> drivers/gpu/drm/arm/malidp_crtc.c | 2 ++ >>> 1 file changed, 2 insertions(+) >>> >>> diff --git a/drivers/gpu/drm/arm/malidp_crtc.c >>> b/drivers/gpu/drm/arm/malidp_crtc.c >>> index 56aad288666e..bb79223d9981 100644 >>> --- a/drivers/gpu/drm/arm/malidp_crtc.c >>> +++ b/drivers/gpu/drm/arm/malidp_crtc.c >>> @@ -36,11 +36,13 @@ static enum drm_mode_status >>> malidp_crtc_mode_valid(struct drm_crtc *crtc, >>> >>> if (req_rate) { >>> rate = clk_round_rate(hwdev->pxlclk, req_rate); >>> +#ifndef CONFIG_ARCH_LAYERSCAPE >> >> What about multiplatform builds? The kernel config doesn't tell you what >> hardware you're actually running on. >> > > Hi Robin, > > Thanks for your reply. > > In fact, Only one platform integrates this IP when CONFIG_ARCH_LAYERSCAPE is set. > Although this are not good ways, but I think it won't be a problem under multiplatform builds.
My point is that ARCH_LAYERSCAPE is going to be enabled in distribution kernels along with everything else, so you're effectively removing this check for all other vendors' Mali-DP implementations as well, which is probably not OK.
Furthermore, if LS1028A really only supports 4 specific modes as the BSP documentation I found claims, then surely you'd want a *more* specific check here, rather than no check at all?
Robin.
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