From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: "Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, "David Müller" <d.mueller@elsoft.ch>,
"Daniel Vetter" <daniel.vetter@ffwll.ch>
Subject: [ 05/12] drm/i915: Fall back to bit banging mode for DVO transmitter detection
Date: Thu, 9 May 2013 15:37:18 -0700 [thread overview]
Message-ID: <20130509223612.008728899@linuxfoundation.org> (raw)
In-Reply-To: <20130509223611.432377360@linuxfoundation.org>
3.0-stable review patch. If anyone has any objections, please let me know.
------------------
From: David Müller <d.mueller@elsoft.ch>
commit e4bfff54ed3f5de88f5358504c78c2cb037813aa upstream.
As discussed in this thread
http://lists.freedesktop.org/archives/dri-devel/2013-April/037411.html
GMBUS based DVO transmitter detection seems to be unreliable which could
result in an unusable DVO port.
The attached patch fixes this by falling back to bit banging mode for
the time DVO transmitter detection is in progress.
Signed-off-by: David Müller <d.mueller@elsoft.ch>
Tested-by: David Müller <d.mueller@elsoft.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/gpu/drm/i915/intel_dvo.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
--- a/drivers/gpu/drm/i915/intel_dvo.c
+++ b/drivers/gpu/drm/i915/intel_dvo.c
@@ -371,6 +371,7 @@ void intel_dvo_init(struct drm_device *d
const struct intel_dvo_device *dvo = &intel_dvo_devices[i];
struct i2c_adapter *i2c;
int gpio;
+ bool dvoinit;
/* Allow the I2C driver info to specify the GPIO to be used in
* special cases, but otherwise default to what's defined
@@ -390,7 +391,17 @@ void intel_dvo_init(struct drm_device *d
i2c = &dev_priv->gmbus[gpio].adapter;
intel_dvo->dev = *dvo;
- if (!dvo->dev_ops->init(&intel_dvo->dev, i2c))
+
+ /* GMBUS NAK handling seems to be unstable, hence let the
+ * transmitter detection run in bit banging mode for now.
+ */
+ intel_gmbus_force_bit(i2c, true);
+
+ dvoinit = dvo->dev_ops->init(&intel_dvo->dev, i2c);
+
+ intel_gmbus_force_bit(i2c, false);
+
+ if (!dvoinit)
continue;
intel_encoder->type = INTEL_OUTPUT_DVO;
next prev parent reply other threads:[~2013-05-09 22:40 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-09 22:37 [ 00/12] 3.0.78-stable review Greg Kroah-Hartman
2013-05-09 22:37 ` [ 01/12] powerpc: fix numa distance for form0 device tree Greg Kroah-Hartman
2013-05-09 22:37 ` [ 02/12] autofs - remove autofs dentry mount check Greg Kroah-Hartman
2013-05-09 22:37 ` [ 03/12] ipvs: ip_vs_sip_fill_param() BUG: bad check of return value Greg Kroah-Hartman
2013-05-09 22:37 ` [ 04/12] drm/i915: Add no-lvds quirk for Fujitsu Esprimo Q900 Greg Kroah-Hartman
2013-05-09 22:37 ` Greg Kroah-Hartman [this message]
2013-05-09 22:37 ` [ 06/12] drm/radeon: dont use get_engine_clock() on APUs Greg Kroah-Hartman
2013-05-09 22:37 ` [ 07/12] drm/radeon/evergreen+: dont enable HPD interrupts on eDP/LVDS Greg Kroah-Hartman
2013-05-09 22:37 ` [ 08/12] drm/radeon: fix endian bugs in atom_allocate_fb_scratch() Greg Kroah-Hartman
2013-05-09 22:37 ` [ 09/12] drm/radeon: fix possible segfault when parsing pm tables Greg Kroah-Hartman
2013-05-09 22:37 ` [ 10/12] tracing: Fix ftrace_dump() Greg Kroah-Hartman
2013-05-09 22:37 ` [ 11/12] kernel/audit_tree.c: tree will leak memory when failure occurs in audit_trim_trees() Greg Kroah-Hartman
2013-05-09 22:37 ` [ 12/12] x86/mm: account for PGDIR_SIZE alignment Greg Kroah-Hartman
2013-05-10 15:26 ` [ 00/12] 3.0.78-stable review Shuah Khan
2013-05-11 5:17 ` Satoru Takeuchi
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