Re: [PATCH] drm/bridge: anx7625: enable DSI EOTP

From: Nicolas Boichat <drinkcat@chromium.org>
To: Andrzej Hajda <a.hajda@samsung.com>
Cc: Robert Foss <robert.foss@linaro.org>,
	devel@driverdev.osuosl.org, Nicolas Boichat <drinkcat@google.com>,
	Jernej Skrabec <jernej.skrabec@siol.net>,
	Sheng Pan <span@analogixsemi.com>,
	Jonas Karlman <jonas@kwiboo.se>, David Airlie <airlied@linux.ie>,
	Neil Armstrong <narmstrong@baylibre.com>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	dri-devel <dri-devel@lists.freedesktop.org>,
	Vasily Khoruzhick <anarsoul@gmail.com>,
	Boris Brezillon <boris.brezillon@collabora.com>,
	Torsten Duwe <duwe@lst.de>,
	Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
	Hsin-Yi Wang <hsinyi@chromium.org>,
	Sam Ravnborg <sam@ravnborg.org>, Xin Ji <xji@analogixsemi.com>,
	Dan Carpenter <dan.carpenter@oracle.com>,
	Marek Szyprowski <m.szyprowski@samsung.com>
Subject: Re: [PATCH] drm/bridge: anx7625: enable DSI EOTP
Date: Fri, 5 Feb 2021 06:25:02 +0800	[thread overview]
Message-ID: <CANMq1KAVMhFAdy_s4R-h1yzNWXRgWgZ4s9kQL11LDze3+Qv5_w@mail.gmail.com> (raw)
In-Reply-To: <b680fef2-7c8a-183b-443a-6b2b9fe595d7@samsung.com>

On Thu, Feb 4, 2021 at 8:59 PM Andrzej Hajda <a.hajda@samsung.com> wrote:
>
>
> W dniu 04.02.2021 o 13:34, Nicolas Boichat pisze:
> > On Thu, Feb 4, 2021 at 8:07 PM Robert Foss <robert.foss@linaro.org> wrote:
> >> Hi Xin,
> >>
> >> Thanks for the patch.
> >>
> >> On Thu, 28 Jan 2021 at 12:17, Xin Ji <xji@analogixsemi.com> wrote:
> >>> Enable DSI EOTP feature for fixing some panel screen constance
> >>> shift issue.
> >>> Removing MIPI flag MIPI_DSI_MODE_EOT_PACKET to enable DSI EOTP.
> >> I don't think I quite understand how removing the
> >> MIPI_DSI_MODE_EOT_PACKET flag will cause DSI EOTP to be enabled. Could
> >> you extrapolate on this in the commit message?
> > That confused me as well, but it turns out that's how the flag is defined:
> > ```
> > /* disable EoT packets in HS mode */
> > #define MIPI_DSI_MODE_EOT_PACKET BIT(9)
> > ```
> > (https://protect2.fireeye.com/v1/url?k=5bd95ebd-044267fb-5bd8d5f2-0cc47a3003e8-ce9db8ea264d6901&q=1&e=900556dc-d199-4c18-9432-5c3465a98eae&u=https%3A%2F%2Felixir.bootlin.com%2Flinux%2Flatest%2Fsource%2Finclude%2Fdrm%2Fdrm_mipi_dsi.h%23L129)
> >
> > I'm almost tempted to put together a mass patch to rename all of these flags...
>
>
> Yes that would be good, many of these flags were just copy pasted from
> some hw datasheet, without good analysis how to adapt them to the framework.

I'll look into it (but that shouldn't block this patch).

>
>
> Regards
>
> Andrzej
>
>
> >
> >>> Signed-off-by: Xin Ji <xji@analogixsemi.com>
> >>> ---
> >>>   drivers/gpu/drm/bridge/analogix/anx7625.c | 1 -
> >>>   1 file changed, 1 deletion(-)
> >>>
> >>> diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.c b/drivers/gpu/drm/bridge/analogix/anx7625.c
> >>> index 65cc059..e31eeb1b 100644
> >>> --- a/drivers/gpu/drm/bridge/analogix/anx7625.c
> >>> +++ b/drivers/gpu/drm/bridge/analogix/anx7625.c
> >>> @@ -1334,7 +1334,6 @@ static int anx7625_attach_dsi(struct anx7625_data *ctx)
> >>>          dsi->format = MIPI_DSI_FMT_RGB888;
> >>>          dsi->mode_flags = MIPI_DSI_MODE_VIDEO   |
> >>>                  MIPI_DSI_MODE_VIDEO_SYNC_PULSE  |
> >>> -               MIPI_DSI_MODE_EOT_PACKET        |
> >>>                  MIPI_DSI_MODE_VIDEO_HSE;
> >>>
> >>>          if (mipi_dsi_attach(dsi) < 0) {
> >>> --
> >>> 2.7.4
> >>>
> > _______________________________________________
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> > dri-devel@lists.freedesktop.org
> > https://protect2.fireeye.com/v1/url?k=457f3f39-1ae4067f-457eb476-0cc47a3003e8-b702072da729d8c9&q=1&e=900556dc-d199-4c18-9432-5c3465a98eae&u=https%3A%2F%2Flists.freedesktop.org%2Fmailman%2Flistinfo%2Fdri-devel
> >