[PATCH] drm/radeon: Fix Asus M2A-VM HDMI EDID error flooding problem
alexdeucher at gmail.com
Wed Jul 6 08:42:42 PDT 2011
On Wed, Jul 6, 2011 at 11:39 AM, Alex Deucher <alexdeucher at gmail.com> wrote:
> On Wed, Jul 6, 2011 at 6:09 AM, <reimth at googlemail.com> wrote:
>> From: Thomas Reim <rdratlos at yahoo.co.uk>
>> Some integrated ATI Radeon chipset implementations
>> with add-on HDMI card (e. g. Asus M2A-VM HDMI) indicate the availability
>> of a DDC even when the add-on card is not plugged in or HDMI is disabled
>> in BIOS setup. In this case, drm_get_edid() and drm_edid_block_valid()
>> periodically dump data and kernel errors into system log files and onto
>> terminals. For these chipsets DDC probing is extended by a check for a
>> correct EDID header. Only in case a valid EDID header is also found, the
>> (HDMI) connector will be used by the Radeon driver. This prevents the
>> kernel driver from useless flooding of logs and terminal sessions with
>> EDID dumps and error messages.
>> This patch adds a flag 'requires_extended_probe' to the radeon_connector
>> structure. In function radeon_connector_needs_extended_probe() this flag
>> can be set on a chipset family/vendor/connector type specific basis.
>> In addition, function drm_edid_header_is_valid() has been added for EDID
>> header check and function radeon_ddc_probe() has been adapted to perform
>> extended DDC probing if required by the connector's flag.
>> Tested for kernel 2.35, 2.38 and 3.0 on Asus M2A-VM HDMI board
> Once it's ready, just add:
> Cc: stable at kernel.org
> to the commit message and it will go into the stable kernels as well.
> Might want to mention the bug report in your commit message as well.
> Just a couple comments below. With those fixed:
> Reviewed-by: Alex Deucher <alexdeucher at gmail.com>
We also may want to revert 4a9a8b71e12d41abb71c4e741bff524f016cfef4
once this patch goes in, otherwise we may remove the ddc bus
unnecessarily on some systems.
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