Re: [PATCH v3 00/15] Improvements and fixes for mxsfb DRM driver

From: "Guido Günther" <agx@sigxcpu•org>
To: Stefan Agner <stefan@agner•ch>
Cc: Marek Vasut <marex@denx•de>, Mark Rutland <mark.rutland@arm•com>,
	Pengutronix Kernel Team <kernel@pengutronix•de>,
	devicetree@vger•kernel.org, David Airlie <airlied@linux•ie>,
	Fabio Estevam <festevam@gmail•com>,
	Sascha Hauer <s.hauer@pengutronix•de>,
	linux-kernel@vger•kernel.org, dri-devel@lists•freedesktop.org,
	Rob Herring <robh+dt@kernel•org>,
	NXP Linux Team <linux-imx@nxp•com>,
	Daniel Vetter <daniel@ffwll•ch>,
	Robert Chiras <robert.chiras@nxp•com>,
	Shawn Guo <shawnguo@kernel•org>,
	linux-arm-kernel@lists•infradead.org
Subject: Re: [PATCH v3 00/15] Improvements and fixes for mxsfb DRM driver
Date: Mon, 26 Aug 2019 18:34:40 +0200	[thread overview]
Message-ID: <20190826163440.GA5539@bogon.m.sigxcpu.org> (raw)
In-Reply-To: <3bd35686e046048d35cd4987567a13cf@agner.ch>

Hi,
On Mon, Aug 26, 2019 at 04:35:10PM +0200, Stefan Agner wrote:
> On 2019-08-26 14:05, Guido Günther wrote:
> > Hi,
> > On Wed, Aug 21, 2019 at 01:15:40PM +0300, Robert Chiras wrote:
> >> This patch-set improves the use of eLCDIF block on iMX 8 SoCs (like 8MQ, 8MM
> >> and 8QXP). Following, are the new features added and fixes from this
> >> patch-set:
> > 
> > I've applied this whole series on top of my NWL work and it looks good
> > with a DSI panel. Applying the whole series also fixes an issue where
> > after unblank the output was sometimes shifted about half a screen width
> > to the right (which didn't happen with DCSS). So at least from the parts
> > I could test:
> > 
> >   Tested-by: Guido Günther <agx@sigxcpu•org> 
> > 
> > for the whole thing.
> 
> Thanks for testing! What SoC did you use? I think it would be good to
> also give this a try on i.MX 7 or i.MX 6ULL before merging.

This was on i.MX8MQ. I don't have hardware to test mxsfb on anything
else over here atm.
Cheers,
 -- Guido

> 
> --
> Stefan
> 
> 
> > Cheers,
> >  -- Guido
> >>
> >> 1. Add support for drm_bridge
> >> On 8MQ and 8MM, the LCDIF block is not directly connected to a parallel
> >> display connector, where an LCD panel can be attached, but instead it is
> >> connected to DSI controller. Since this DSI stands between the display
> >> controller (eLCDIF) and the physical connector, the DSI can be implemented
> >> as a DRM bridge. So, in order to be able to connect the mxsfb driver to
> >> the DSI driver, the support for a drm_bridge was needed in mxsfb DRM
> >> driver (the actual driver for the eLCDIF block).
> >>
> >> 2. Add support for additional pixel formats
> >> Some of the pixel formats needed by Android were not implemented in this
> >> driver, but they were actually supported. So, add support for them.
> >>
> >> 3. Add support for horizontal stride
> >> Having support for horizontal stride allows the use of eLCDIF with a GPU
> >> (for example) that can only output resolution sizes multiple of a power of
> >> 8. For example, 1080 is not a power of 16, so in order to support 1920x1080
> >> output from GPUs that can produce linear buffers only in sizes multiple to 16,
> >> this feature is needed.
> >>
> >> 3. Few minor features and bug-fixing
> >> The addition of max-res DT property was actually needed in order to limit
> >> the bandwidth usage of the eLCDIF block. This is need on systems where
> >> multiple display controllers are presend and the memory bandwidth is not
> >> enough to handle all of them at maximum capacity (like it is the case on
> >> 8MQ, where there are two display controllers: DCSS and eLCDIF).
> >> The rest of the patches are bug-fixes.
> >>
> >> v3:
> >> - Removed the max-res property patches and added support for
> >>   max-memory-bandwidth property, as it is also implemented in other drivers
> >> - Removed unnecessary drm_vblank_off in probe
> >>
> >> v2:
> >> - Collected Tested-by from Guido
> >> - Split the first patch, which added more than one feature into relevant
> >>   patches, explaining each feature added
> >> - Also split the second patch into more patches, to differentiate between
> >>   the feature itself (additional pixel formats support) and the cleanup
> >>   of the register definitions for a better representation (guido)
> >> - Included a patch submitted by Guido, while he was testing my patch-set
> >>
> >> Guido Günther (1):
> >>   drm/mxsfb: Read bus flags from bridge if present
> >>
> >> Mirela Rabulea (1):
> >>   drm/mxsfb: Signal mode changed when bpp changed
> >>
> >> Robert Chiras (13):
> >>   drm/mxsfb: Update mxsfb to support a bridge
> >>   drm/mxsfb: Add defines for the rest of registers
> >>   drm/mxsfb: Reset vital registers for a proper initialization
> >>   drm/mxsfb: Update register definitions using bit manipulation defines
> >>   drm/mxsfb: Update mxsfb with additional pixel formats
> >>   drm/mxsfb: Fix the vblank events
> >>   drm/mxsfb: Add max-memory-bandwidth property for MXSFB
> >>   dt-bindings: display: Add max-memory-bandwidth property for mxsfb
> >>   drm/mxsfb: Update mxsfb to support LCD reset
> >>   drm/mxsfb: Improve the axi clock usage
> >>   drm/mxsfb: Clear OUTSTANDING_REQS bits
> >>   drm/mxsfb: Add support for horizontal stride
> >>   drm/mxsfb: Add support for live pixel format change
> >>
> >>  .../devicetree/bindings/display/mxsfb.txt          |   5 +
> >>  drivers/gpu/drm/mxsfb/mxsfb_crtc.c                 | 287 ++++++++++++++++++---
> >>  drivers/gpu/drm/mxsfb/mxsfb_drv.c                  | 203 +++++++++++++--
> >>  drivers/gpu/drm/mxsfb/mxsfb_drv.h                  |  12 +-
> >>  drivers/gpu/drm/mxsfb/mxsfb_out.c                  |  26 +-
> >>  drivers/gpu/drm/mxsfb/mxsfb_regs.h                 | 193 +++++++++-----
> >>  6 files changed, 589 insertions(+), 137 deletions(-)
> >>
> >> --
> >> 2.7.4
> >>
> 

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