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From: Daniel Vetter <daniel@ffwll.ch>
To: Keith Packard <keithp@keithp.com>
Cc: Dave Airlie <airlied@redhat.com>,
	intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org,
	dri-devel@lists.freedesktop.org
Subject: Re: [PATCH 14/21] drm/i915: Correct eDP panel power sequencing delay computations
Date: Fri, 30 Sep 2011 20:16:44 +0200	[thread overview]
Message-ID: <20110930181644.GR2859@phenom.ffwll.local> (raw)
In-Reply-To: <1317344993-24945-15-git-send-email-keithp@keithp.com>

On Thu, Sep 29, 2011 at 06:09:46PM -0700, Keith Packard wrote:
> Store the panel power sequencing delays in the dp private structure,
> rather than the global device structure. Who knows, maybe we'll get
> more than one eDP device in the future.
> 
> Look at both the current hardware register settings and the VBT
> specified panel power sequencing timings. Use the maximum of the two
> delays, to make sure things work reliably. If there is no VBT data,
> then those values will be initialized to zero, so we'll just use the
> values as programmed in the hardware.
> 
> This patch computes power-up and power-down delays, rather than using
> portions of the appropriate delay values as found in the hardware. The
> eDP specified delay between raising VCC and communicating over the aux
> channel includes both the power rise time (T1) and the aux channel
> communication delay (T3). The eDP specified delay between powering
> down the device and powering it back up includes both the power fall
> time (T11) and the device idle time (T12).
> 
> From the hardware, I'm taking the T3 value from the PP_OFF_DELAYS
> Power_Down_delay value, which is actually documented to be the 'T3
> time sequence' value used 'during power up'. There aren't separate T1
> and T2 values, but there is a combined T1+T2 value in the PP_ON_DELAYS
> register, so I use that instead.
> 
> VBT doesn't provide any values for T1 or T2, so we'll always just use
> the hardware value for that.
> 
> The panel power up delay is thus T1 + T2 + T3, which should be
> sufficient in all cases.
> 
> The panel power down delay is T1 + T2 + T12, using T1+T2 as a proxy
> for T11, which isn't available anywhere.
> 
> On the macbook air I'm testing with, this yields a power-up delay of
> over 200ms and a power-down delay of over 600ms. It all works now, but
> we're frobbing these power controls several times during mode setting,
> making the whole process take an awfully long time.
> 
> Signed-off-by: Keith Packard <keithp@keithp.com>

Awesome patch description and the code agrees with what I've cross-checked
on bspec. The only fear I have is that we currently ignore the backlight
on/off timings and some panel probably relies on use waiting for backlight
on/off + panel on/off in total. But that's material for another patch.

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
-- 
Daniel Vetter
Mail: daniel@ffwll.ch
Mobile: +41 (0)79 365 57 48

  reply	other threads:[~2011-09-30 18:16 UTC|newest]

Thread overview: 101+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-09-19 22:21 drm/i915: eDP cleanup patch series -- fixes SNB MacBook Air Keith Packard
2011-09-19 22:21 ` [PATCH 1/9] drm/i915: Enable digital port hotplug on PCH systems Keith Packard
2011-09-19 22:21 ` [PATCH 2/9] drm/i915: Remove extra 300ms delay during eDP mode setting Keith Packard
2011-09-19 22:21 ` [PATCH 3/9] drm/i915: Only use VBT panel mode on eDP if no EDID is found Keith Packard
2011-09-19 22:21 ` [PATCH 4/9] drm/i915: Check eDP power when doing aux channel communications Keith Packard
2011-09-19 22:21 ` [PATCH 5/9] drm/i915: Unlock PCH_PP_CONTROL always Keith Packard
2011-09-19 22:22 ` [PATCH 6/9] drm/i915: Make sure eDP power is on before using aux channel Keith Packard
2011-09-21  3:50   ` Jesse Barnes
2011-09-21  4:45     ` [Intel-gfx] " Keith Packard
2011-09-23  2:55       ` Jesse Barnes
2011-09-23  5:07         ` [Intel-gfx] " Keith Packard
2011-09-19 22:22 ` [PATCH 7/9] drm/i915: Correct eDP panel power sequencing delay computations Keith Packard
2011-09-19 22:22 ` [PATCH 8/9] drm/i915: Move eDP panel fixed mode from dev_priv to intel_dp Keith Packard
2011-09-19 22:22 ` [PATCH 9/9] drm/i915: Disable eDP VDD in a delayed work proc instead of synchronously Keith Packard
2011-09-21  4:17   ` [Intel-gfx] " Jesse Barnes
2011-09-21  4:51     ` Keith Packard
2011-09-23  3:22       ` Jesse Barnes
2011-09-30  1:09         ` [PATCH 00/24] MacBook Air patch sequence (v2) Keith Packard
2011-09-30  1:09           ` [PATCH 01/21] drm/i915: Enable digital port hotplug on PCH systems Keith Packard
2011-09-30 16:17             ` [Intel-gfx] " Daniel Vetter
2011-10-03 20:34               ` Jesse Barnes
2011-09-30  1:09           ` [PATCH 02/21] drm/i915: Shut down PCH interrupts during irq_uninstall Keith Packard
2011-09-30 16:20             ` Daniel Vetter
2011-09-30 17:44               ` Keith Packard
2011-09-30 17:56                 ` Daniel Vetter
2011-09-30  1:09           ` [PATCH 03/21] drm/i915: Remove extra 300ms delay during eDP mode setting Keith Packard
2011-09-30 16:27             ` Daniel Vetter
2011-09-30 17:50               ` Keith Packard
2011-09-30 17:58                 ` Daniel Vetter
2011-09-30 18:09                   ` Daniel Vetter
2011-09-30 18:28                     ` Keith Packard
2011-09-30  1:09           ` [PATCH 04/21] drm/i915: Only use VBT panel mode on eDP if no EDID is found Keith Packard
2011-09-30 16:32             ` Daniel Vetter
2011-09-30 17:58               ` Keith Packard
2011-10-03 20:42                 ` [Intel-gfx] " Jesse Barnes
2011-09-30  1:09           ` [PATCH 05/21] drm/i915: Check eDP power when doing aux channel communications Keith Packard
2011-09-30 17:02             ` [Intel-gfx] " Daniel Vetter
2011-09-30 18:01               ` Keith Packard
2011-09-30 18:11                 ` Daniel Vetter
2011-09-30 18:23                 ` Chris Wilson
2011-10-03 20:48             ` Jesse Barnes
2011-09-30  1:09           ` [PATCH 06/21] drm/i915: Unlock PCH_PP_CONTROL always Keith Packard
2011-09-30 17:09             ` [Intel-gfx] " Daniel Vetter
2011-09-30 18:01               ` Keith Packard
2011-09-30 23:14               ` Keith Packard
2011-10-01  9:35                 ` Daniel Vetter
2011-09-30  1:09           ` [PATCH 07/21] drm/i915: Check for eDP inside intel_edp_panel_vdd_on/off Keith Packard
2011-09-30 17:13             ` [Intel-gfx] " Daniel Vetter
2011-09-30 18:02               ` Keith Packard
2011-09-30  1:09           ` [PATCH 08/21] drm/i915: Turn force VDD back off when panel running in intel_dp_dpms Keith Packard
2011-09-30 17:15             ` [Intel-gfx] " Daniel Vetter
2011-09-30  1:09           ` [PATCH 09/21] drm/i915: Delay DP i2c initialization until panel power timings are computed Keith Packard
2011-09-30 17:25             ` [Intel-gfx] " Daniel Vetter
2011-09-30  1:09           ` [PATCH 10/21] drm/i915: Wrap DP EDID fetch functions to enable eDP panel power Keith Packard
2011-09-30 17:32             ` Daniel Vetter
2011-10-03 20:59             ` [Intel-gfx] " Jesse Barnes
2011-09-30  1:09           ` [PATCH 11/21] drm/i915: Enable eDP panel power during I2C initialization sequence Keith Packard
2011-09-30 17:26             ` Daniel Vetter
2011-09-30  1:09           ` [PATCH 12/21] drm/i915: Ensure eDP powered up during DP_SET_POWER operation in dp_prepare Keith Packard
2011-09-30 17:45             ` Daniel Vetter
2011-09-30 18:30               ` Keith Packard
2011-09-30  1:09           ` [PATCH 13/21] drm/i915: Place long delays after each eDP VDD operation Keith Packard
2011-09-30 18:01             ` [Intel-gfx] " Daniel Vetter
2011-09-30 18:31               ` Keith Packard
2011-09-30  1:09           ` [PATCH 14/21] drm/i915: Correct eDP panel power sequencing delay computations Keith Packard
2011-09-30 18:16             ` Daniel Vetter [this message]
2011-09-30 18:33               ` Keith Packard
2011-10-01  3:31               ` Keith Packard
2011-10-01  9:59                 ` Daniel Vetter
2011-10-01 19:01                   ` Keith Packard
2011-10-03 10:10                     ` Daniel Vetter
2011-09-30  1:09           ` [PATCH 15/21] drm/i915: Move eDP panel fixed mode from dev_priv to intel_dp Keith Packard
2011-09-30 18:20             ` [Intel-gfx] " Daniel Vetter
2011-09-30  1:09           ` [PATCH 16/21] drm/i915: edp_panel_on does not need to return a bool Keith Packard
2011-09-30 18:21             ` Daniel Vetter
2011-10-03 21:03             ` [Intel-gfx] " Jesse Barnes
2011-09-30  1:09           ` [PATCH 17/21] drm/i915: Create helper functions to determine eDP power state Keith Packard
2011-09-30 18:26             ` [Intel-gfx] " Daniel Vetter
2011-09-30  1:09           ` [PATCH 18/21] drm/i915: Disable eDP VDD in a delayed work proc instead of synchronously Keith Packard
2011-09-30 10:31             ` Chris Wilson
2011-09-30 18:06               ` Keith Packard
2011-09-30 18:47             ` Daniel Vetter
2011-09-30 20:56               ` Keith Packard
2011-09-30 22:01                 ` Daniel Vetter
2011-09-30  1:09           ` [PATCH 19/21] drm/i915: Asynchronous eDP panel power off Keith Packard
2011-09-30 18:55             ` Daniel Vetter
2011-09-30 20:57               ` Keith Packard
2011-10-12 14:41             ` Dave Airlie
2011-10-12 16:43               ` Keith Packard
2011-09-30  1:09           ` [PATCH 20/21] drm/i915: Restrict ILK-specific eDP power hack to ILK Keith Packard
2011-09-30 18:57             ` Daniel Vetter
2011-09-30  1:09           ` [PATCH 21/21] drm/i915: No need to wait for eDP power off delay if panel is on Keith Packard
2011-09-30 19:01             ` Daniel Vetter
2011-09-30  3:33           ` [PATCH 00/24] MacBook Air patch sequence (v2) Greg KH
2011-09-30  8:58             ` Keith Packard
2011-09-30 13:57               ` Greg KH
2011-09-30 18:10                 ` Keith Packard
2011-09-30 13:20             ` Ted Ts'o
2011-09-30 18:17               ` Keith Packard
2011-10-03 21:06                 ` [Intel-gfx] " Jesse Barnes
2011-10-11  8:04           ` Chris Wilson

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