From: Daniel Vetter <daniel@ffwll.ch>
To: Thierry Reding <thierry.reding@gmail.com>
Cc: Eric Anholt <eric@anholt.net>,
Mark Rutland <mark.rutland@arm.com>,
Florian Fainelli <f.fainelli@gmail.com>,
Stephen Warren <swarren@wwwdotorg.org>,
Michael Turquette <mturquette@baylibre.com>,
Lee Jones <lee@kernel.org>, Stephen Boyd <sboyd@codeaurora.org>,
linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
Rob Herring <robh+dt@kernel.org>,
bcm-kernel-feedback-list@broadcom.com,
linux-rpi-kernel@lists.infradead.org, linux-clk@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 09/11] drm/panel: Add support for the Raspberry Pi 7" Touchscreen.
Date: Tue, 31 Jan 2017 22:17:02 +0100 [thread overview]
Message-ID: <20170131211702.o2he5o6ktaztmrkx@phenom.ffwll.local> (raw)
In-Reply-To: <20170131210717.GA872@mithrandir.ba.sec>
On Tue, Jan 31, 2017 at 10:07:19PM +0100, Thierry Reding wrote:
> On Wed, Dec 14, 2016 at 11:46:19AM -0800, Eric Anholt wrote:
> > +static int rpi_touchscreen_enable(struct drm_panel *panel)
> > +{
> > + struct rpi_touchscreen *ts = panel_to_ts(panel);
> > + int i;
> > +
> > + rpi_touchscreen_i2c_write(ts, REG_POWERON, 1);
> > + /* Wait for nPWRDWN to go low to indicate poweron is done. */
> > + for (i = 0; i < 100; i++) {
> > + if (rpi_touchscreen_i2c_read(ts, REG_PORTB) & 1)
> > + break;
> > + }
>
> Don't you want to fail when power on doesn't succeed? Seems kind of
> pointless to continue if the panel doesn't power on.
kms works under the assumption that even when the sink is dead, the
display pipe (well, vblanks and pageflips) keep working. There's a patch
floating around to give userspace more information about what's going
wrong through an async uevent+read-only property for cases where an
unresponsive sink is normal, i.e. link training for dp.
But either way, continuing is generally the right thing to do, there's no
way to report -EIO from here (because no reasons than that's where
accidentally ended up with our evolved design ...).
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
WARNING: multiple messages have this Message-ID (diff)
From: daniel@ffwll.ch (Daniel Vetter)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 09/11] drm/panel: Add support for the Raspberry Pi 7" Touchscreen.
Date: Tue, 31 Jan 2017 22:17:02 +0100 [thread overview]
Message-ID: <20170131211702.o2he5o6ktaztmrkx@phenom.ffwll.local> (raw)
In-Reply-To: <20170131210717.GA872@mithrandir.ba.sec>
On Tue, Jan 31, 2017 at 10:07:19PM +0100, Thierry Reding wrote:
> On Wed, Dec 14, 2016 at 11:46:19AM -0800, Eric Anholt wrote:
> > +static int rpi_touchscreen_enable(struct drm_panel *panel)
> > +{
> > + struct rpi_touchscreen *ts = panel_to_ts(panel);
> > + int i;
> > +
> > + rpi_touchscreen_i2c_write(ts, REG_POWERON, 1);
> > + /* Wait for nPWRDWN to go low to indicate poweron is done. */
> > + for (i = 0; i < 100; i++) {
> > + if (rpi_touchscreen_i2c_read(ts, REG_PORTB) & 1)
> > + break;
> > + }
>
> Don't you want to fail when power on doesn't succeed? Seems kind of
> pointless to continue if the panel doesn't power on.
kms works under the assumption that even when the sink is dead, the
display pipe (well, vblanks and pageflips) keep working. There's a patch
floating around to give userspace more information about what's going
wrong through an async uevent+read-only property for cases where an
unresponsive sink is normal, i.e. link training for dp.
But either way, continuing is generally the right thing to do, there's no
way to report -EIO from here (because no reasons than that's where
accidentally ended up with our evolved design ...).
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
WARNING: multiple messages have this Message-ID (diff)
From: Daniel Vetter <daniel@ffwll.ch>
To: Thierry Reding <thierry.reding@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>,
Florian Fainelli <f.fainelli@gmail.com>,
Stephen Warren <swarren@wwwdotorg.org>,
Michael Turquette <mturquette@baylibre.com>,
Lee Jones <lee@kernel.org>, Stephen Boyd <sboyd@codeaurora.org>,
linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
Rob Herring <robh+dt@kernel.org>,
bcm-kernel-feedback-list@broadcom.com,
linux-rpi-kernel@lists.infradead.org, linux-clk@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 09/11] drm/panel: Add support for the Raspberry Pi 7" Touchscreen.
Date: Tue, 31 Jan 2017 22:17:02 +0100 [thread overview]
Message-ID: <20170131211702.o2he5o6ktaztmrkx@phenom.ffwll.local> (raw)
In-Reply-To: <20170131210717.GA872@mithrandir.ba.sec>
On Tue, Jan 31, 2017 at 10:07:19PM +0100, Thierry Reding wrote:
> On Wed, Dec 14, 2016 at 11:46:19AM -0800, Eric Anholt wrote:
> > +static int rpi_touchscreen_enable(struct drm_panel *panel)
> > +{
> > + struct rpi_touchscreen *ts = panel_to_ts(panel);
> > + int i;
> > +
> > + rpi_touchscreen_i2c_write(ts, REG_POWERON, 1);
> > + /* Wait for nPWRDWN to go low to indicate poweron is done. */
> > + for (i = 0; i < 100; i++) {
> > + if (rpi_touchscreen_i2c_read(ts, REG_PORTB) & 1)
> > + break;
> > + }
>
> Don't you want to fail when power on doesn't succeed? Seems kind of
> pointless to continue if the panel doesn't power on.
kms works under the assumption that even when the sink is dead, the
display pipe (well, vblanks and pageflips) keep working. There's a patch
floating around to give userspace more information about what's going
wrong through an async uevent+read-only property for cases where an
unresponsive sink is normal, i.e. link training for dp.
But either way, continuing is generally the right thing to do, there's no
way to report -EIO from here (because no reasons than that's where
accidentally ended up with our evolved design ...).
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel
next prev parent reply other threads:[~2017-01-31 21:27 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-14 19:46 [PATCH 00/11] drm/vc4: DSI panel support + Raspberry Pi touchscreen Eric Anholt
2016-12-14 19:46 ` Eric Anholt
2016-12-14 19:46 ` [PATCH 01/11] clk: bcm2835: Don't rate change PLLs on behalf of DSI PLL dividers Eric Anholt
2016-12-14 19:46 ` Eric Anholt
2016-12-14 19:46 ` Eric Anholt
2016-12-14 19:46 ` [PATCH 02/11] clk: bcm2835: Register the DSI0/DSI1 pixel clocks Eric Anholt
2016-12-14 19:46 ` Eric Anholt
2016-12-14 19:46 ` Eric Anholt
2016-12-21 23:14 ` Stephen Boyd
2016-12-21 23:14 ` Stephen Boyd
2016-12-21 23:14 ` Stephen Boyd
2016-12-22 1:23 ` Eric Anholt
2016-12-22 1:23 ` Eric Anholt
2016-12-22 1:23 ` Eric Anholt
2016-12-14 19:46 ` [PATCH 03/11] clk: bcm2835: Add leaf clock measurement support, disabled by default Eric Anholt
2016-12-14 19:46 ` Eric Anholt
2016-12-14 19:46 ` Eric Anholt
2016-12-14 19:46 ` [PATCH 04/11] drm/vc4: Set up SCALER_DISPCTRL at boot Eric Anholt
2016-12-14 19:46 ` Eric Anholt
2017-01-31 19:35 ` Daniel Vetter
2017-01-31 19:35 ` Daniel Vetter
2017-01-31 19:35 ` Daniel Vetter
2016-12-14 19:46 ` [PATCH 05/11] drm/vc4: Add support for feeding DSI encoders from the pixel valve Eric Anholt
2016-12-14 19:46 ` Eric Anholt
2017-01-31 19:39 ` Daniel Vetter
2017-01-31 19:39 ` Daniel Vetter
2017-01-31 19:39 ` Daniel Vetter
2017-01-31 19:54 ` Eric Anholt
2017-01-31 19:54 ` Eric Anholt
2017-01-31 19:54 ` Eric Anholt
2016-12-14 19:46 ` [PATCH 06/11] dt-bindings: Document the VC4 DSI module nodes Eric Anholt
2016-12-14 19:46 ` Eric Anholt
2016-12-14 19:46 ` Eric Anholt
2016-12-14 19:46 ` [PATCH 07/11] drm/vc4: Add DSI driver Eric Anholt
2016-12-14 19:46 ` Eric Anholt
2016-12-14 19:46 ` Eric Anholt
2017-01-31 19:51 ` Daniel Vetter
2017-01-31 19:51 ` Daniel Vetter
2017-01-31 19:51 ` Daniel Vetter
2016-12-14 19:46 ` [PATCH 08/11] dt-bindings: Document the Raspberry Pi Touchscreen nodes Eric Anholt
2016-12-14 19:46 ` Eric Anholt
2016-12-14 19:46 ` Eric Anholt
2016-12-14 19:46 ` [PATCH 09/11] drm/panel: Add support for the Raspberry Pi 7" Touchscreen Eric Anholt
2016-12-14 19:46 ` Eric Anholt
2016-12-14 19:46 ` Eric Anholt
2017-01-31 21:07 ` Thierry Reding
2017-01-31 21:07 ` Thierry Reding
2017-01-31 21:07 ` Thierry Reding
2017-01-31 21:17 ` Daniel Vetter [this message]
2017-01-31 21:17 ` Daniel Vetter
2017-01-31 21:17 ` Daniel Vetter
2017-01-31 21:42 ` Thierry Reding
2017-01-31 21:42 ` Thierry Reding
2017-01-31 21:42 ` Thierry Reding
2017-01-31 21:19 ` Daniel Vetter
2017-01-31 21:19 ` Daniel Vetter
2017-01-31 21:19 ` Daniel Vetter
2017-01-31 21:38 ` Thierry Reding
2017-01-31 21:38 ` Thierry Reding
2016-12-14 19:46 ` [PATCH 10/11] ARM: bcm2835: dt: Add the DSI module nodes and clocks Eric Anholt
2016-12-14 19:46 ` Eric Anholt
2016-12-14 19:46 ` [PATCH 11/11] ARM: bcm2835: Enable the Raspberry Pi touchscreen panel Eric Anholt
2016-12-14 19:46 ` Eric Anholt
2016-12-14 19:46 ` Eric Anholt
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