From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laurent Pinchart Subject: Re: [PATCH v4 13/14] drm/mxsfb: Add support for horizontal stride Date: Wed, 6 Nov 2019 00:12:30 +0200 Message-ID: <20191105221230.GI4869@pendragon.ideasonboard.com> References: <1567078215-31601-1-git-send-email-robert.chiras@nxp.com> <1567078215-31601-14-git-send-email-robert.chiras@nxp.com> <3f346b1f809e77d343117dabc00c0402@agner.ch> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: Content-Disposition: inline In-Reply-To: <3f346b1f809e77d343117dabc00c0402@agner.ch> Sender: linux-kernel-owner@vger.kernel.org To: Stefan Agner Cc: Robert Chiras , Marek Vasut , Mark Rutland , Pengutronix Kernel Team , devicetree@vger.kernel.org, David Airlie , Guido =?utf-8?Q?G=C3=BCnther?= , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Rob Herring , NXP Linux Team , Shawn Guo , Sascha Hauer , linux-arm-kernel@lists.infradead.org List-Id: dri-devel@lists.freedesktop.org On Mon, Oct 14, 2019 at 02:40:55PM +0200, Stefan Agner wrote: > Hi Robert, > > Sorry it took me so long to have a closer look at this patchset. > > I will definitely merge part of it, but this particular patch actually > breaks i.MX 7. I have vertical stripes on my display with this patch > applied (using Weston with DRM backend). Not sure why this exactly > happens, from what I understand this should only affect IP Version 4. The code tests for ipversion >= 4, which should match the i.MX7. > Some notes below: > > On 2019-08-29 13:30, Robert Chiras wrote: > > Besides the eLCDIF block, there is another IP block, used in the past > > for EPDC panels. Since the iMX.8mq doesn't have an EPDC connector, this > > block is not documented, but we can use it to do additional operations > > on the frame buffer. > > Hm, but this block is part of the ELCDIF block, in terms of clock, power > domain etc? On i.MX7 the EPDC IP core is present as the SoC has an EPDC output. Can the EPDC be used to control LCDIF stride on the i.MX7 too ? > > In this case, we can use the pigeon registers from this IP block in > > order to do horizontal crop on the frame buffer processed by the eLCDIF > > block. > > > > Signed-off-by: Robert Chiras > > Tested-by: Guido Günther > > --- > > drivers/gpu/drm/mxsfb/mxsfb_crtc.c | 79 ++++++++++++++++++++++++++++++++++++-- > > drivers/gpu/drm/mxsfb/mxsfb_drv.c | 1 + > > drivers/gpu/drm/mxsfb/mxsfb_regs.h | 16 ++++++++ > > 3 files changed, 92 insertions(+), 4 deletions(-) > > > > diff --git a/drivers/gpu/drm/mxsfb/mxsfb_crtc.c > > b/drivers/gpu/drm/mxsfb/mxsfb_crtc.c > > index a12f53d..317575e 100644 > > --- a/drivers/gpu/drm/mxsfb/mxsfb_crtc.c > > +++ b/drivers/gpu/drm/mxsfb/mxsfb_crtc.c > > @@ -15,6 +15,7 @@ > > > > #include