OpenCloudOS-Kernel/drivers/gpu
Ville Syrjälä 3e4d44e0fa drm/i915: Restore GMBUS operation after a failed bit-banging fallback
When the GMBUS based i2c transfer times out, we try to fall back to
bit-banging and retry the operation that way. However if the bit-banging
attempt also fails, we should probably go back to the GMBUS method for
the next attempt. Maybe there simply wasn't anyone one the bus at this
time.

There's also a bit of a mess going on with the force_bit handling.
It's supposed to be a ref count actually, and it is as far as
intel_gmbus_force_bit() is concerned. But it's treated as just a
flag by the timeout based bit-banging fallback. I suppose that's
fine since we should never end up in the timeout fallback case
if force_bit was already non-zero. However now that we want to restore
things back to where they were after the bit-banging attempt failed,
we're going to have to do things a bit differently to avoid clobbering
the force_bit count as set up by intel_gmbus_force_bit(). So let's
dedicate the high bit as a flag for the low level timeout based fallback
and treat the rest of the bits as a ref count just as before.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1457366220-29409-4-git-send-email-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
2016-04-12 13:20:58 +03:00
..
drm drm/i915: Restore GMBUS operation after a failed bit-banging fallback 2016-04-12 13:20:58 +03:00
host1x Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2016-03-21 13:48:00 -07:00
ipu-v3 gpu: ipu-v3: ipu-dmfc: Rename ipu_dmfc_init_channel to ipu_dmfc_config_wait4eot 2016-03-31 11:24:33 +02:00
vga vga_switcheroo: Add support for switching only the DDC 2016-02-09 11:21:07 +01:00
Makefile