Attachment 100625 Details for Bug 76520 – [PATCH] drm/i915: Populate pipe_config.pixel_multiplier even for disabled pipes

[patch] [PATCH] drm/i915: Populate pipe_config.pixel_multiplier even for disabled pipes

0001-drm-i915-Populate-pipe_config.pixel_multiplier-even-.patch (text/plain), 3.08 KB, created by Ville Syrjala on 2014-06-07 22:58:00 UTC

(hide)

Description:

Filename:

MIME Type:

Creator: Ville Syrjala

Created: 2014-06-07 22:58:00 UTC

Size: 3.08 KB

patch

obsolete

>From ce33dc74e8c6eb426ed5913990fa0cfc6e7de614 Mon Sep 17 00:00:00 2001
>From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala@linux.intel.com>
>Date: Sun, 8 Jun 2014 01:05:28 +0300
>Subject: [PATCH] drm/i915: Populate pipe_config.pixel_multiplier even for
> disabled pipes
>MIME-Version: 1.0
>Content-Type: text/plain; charset=UTF-8
>Content-Transfer-Encoding: 8bit
>
>On certain platforms pixel_multiplier is read out in
>.get_pipe_config(), but it also gets used to calculate the
>pixel clock in intel_sdvo_get_config(). If the pipe is disable
>but some SDVO outputs are active, we may end up dividing by zero
>in intel_sdvo_get_config().
>
>To avoid the problem, populate pipe_config->pixel_multiplier to
>1 even for disabled pipes in {i9xx,ironlake}_get_pipe_config().
>
>The "divide by pixel_multiplier" operation got introduced here:
> commit 18442d08786472c63a0a80c27f92b033dffc26de
> Author: Ville SyrjÃ¤lÃ¤ <ville.syrjala@linux.intel.com>
> Date:   Fri Sep 13 16:00:08 2013 +0300
>
>    drm/i915: Fix port_clock and adjusted_mode.clock readout all over
>
>and it has caused a regression on certain machines since they would
>hit the div-by-zero during resume.
>
>XXX: Remove debug WARN_ON() from intel_sdvo_get_hw_state()
>     It's just included to confirm the theory that the port
>     is disabled while outputs are active
>
>Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=76520
>Cc: <stable@vger.kernel.org> # 3.13+
>Signed-off-by: Ville SyrjÃ¤lÃ¤ <ville.syrjala@linux.intel.com>
>---
> drivers/gpu/drm/i915/intel_display.c | 12 ++++++++++++
> drivers/gpu/drm/i915/intel_sdvo.c    |  2 ++
> 2 files changed, 14 insertions(+)
>
>diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
>index 98b7049..c18a62f 100644
>--- a/drivers/gpu/drm/i915/intel_display.c
>+++ b/drivers/gpu/drm/i915/intel_display.c
>@@ -6164,6 +6164,12 @@ static bool i9xx_get_pipe_config(struct intel_crtc *crtc,
> 	struct drm_i915_private *dev_priv = dev->dev_private;
> 	uint32_t tmp;
> 
>+	/*
>+	 * Avoids a div-by-zero in intel_sdvo_get_config() in
>+	 * case the encoder was enabled, but the pipe wasn't.
>+	 */
>+	pipe_config->pixel_multiplier = 1;
>+
> 	if (!intel_display_power_enabled(dev_priv,
> 					 POWER_DOMAIN_PIPE(crtc->pipe)))
> 		return false;
>@@ -7156,6 +7162,12 @@ static bool ironlake_get_pipe_config(struct intel_crtc *crtc,
> 	pipe_config->cpu_transcoder = (enum transcoder) crtc->pipe;
> 	pipe_config->shared_dpll = DPLL_ID_PRIVATE;
> 
>+	/*
>+	 * Avoids a div-by-zero in intel_sdvo_get_config() in
>+	 * case an encoder was enabled, but the pipe wasn't.
>+	 */
>+	pipe_config->pixel_multiplier = 1;
>+
> 	tmp = I915_READ(PIPECONF(crtc->pipe));
> 	if (!(tmp & PIPECONF_ENABLE))
> 		return false;
>diff --git a/drivers/gpu/drm/i915/intel_sdvo.c b/drivers/gpu/drm/i915/intel_sdvo.c
>index 6a4d5bc..ddbfa3a 100644
>--- a/drivers/gpu/drm/i915/intel_sdvo.c
>+++ b/drivers/gpu/drm/i915/intel_sdvo.c
>@@ -1329,6 +1329,8 @@ static bool intel_sdvo_get_hw_state(struct intel_encoder *encoder,
> 	if (!(tmp & SDVO_ENABLE) && (active_outputs == 0))
> 		return false;
> 
>+	WARN_ON(!(tmp & SDVO_ENABLE));
>+
> 	if (HAS_PCH_CPT(dev))
> 		*pipe = PORT_TO_PIPE_CPT(tmp);
> 	else
>-- 
>1.8.3.2
>

Actions: View | Splinter Review

Attachments on bug 76520: 96282 | 97635 | 97636 | 97637 | 98841 | 100625 | 100674 | 100699 | 100714 | 100715 | 100718 | 100733

Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct. How we collect and use information is described in our Privacy Policy.