linux/drivers/gpu
Shobhit Kumar e12d499e9a drm/i915: Correct the IOSF Dev_FN field for IOSF transfers
commit d180d2bbb6 upstream.

As per the specififcation, the SB_DevFn is the PCI_DEVFN of the target
device and not the source. So PCI_DEVFN(2,0) is not correct. Further the
port ID should be enough to identify devices unless they are MFD. The
SB_DevFn was intended to remove ambiguity in case of these MFD devices.

For non MFD devices the recommendation for the target device IP was to
ignore these fields, but not all of them followed the recommendation.
Some like CCK ignore these fields and hence PCI_DEVFN(2, 0) works and so
does PCI_DEVFN(0, 0) as it works for DPIO. The issue came to light because
of GPIONC which was not getting programmed correctly with PCI_DEVFN(2, 0).
It turned out that this did not follow the recommendation and expected 0
in this field.

In general the recommendation is to use SB_DevFn as PCI_DEVFN(0, 0) for
all devices except target PCI devices.

Signed-off-by: Shobhit Kumar <shobhit.kumar@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
History 2015-03-14 15:37:18 -04:00
..
drm drm/i915: Correct the IOSF Dev_FN field for IOSF transfers 2015-03-14 15:37:18 -04:00
host1x drm/tegra: Make job submission 64-bit safe 2014-08-04 10:07:36 +02:00
ipu-v3 IPUv3 fixes for v3.18 2014-10-07 14:31:14 +10:00
vga Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-10-13 16:23:15 +02:00
Makefile gpu: ipu-v3: Move i.MX IPUv3 core driver out of staging 2014-06-04 11:06:52 +02:00