linux/drivers/gpu
Imre Deak 09eac82772 drm/i915/tgl+: Fix TBT DPLL fractional divider for 38.4MHz ref clock
When the reference clock is 38.4MHz, using the current TBT PLL
fractional divider value results in a slightly off TBT link frequency.
This causes an endless loop of link training success followed by a bad
link signaling and retraining at least on a Dell WD19TB TBT dock.  The
workaround provided by the HW team is to divide the fractional divider
value by two. This fixed the link training problem on the ThinkPad dock.

The same workaround is needed on some EHL platforms and for combo PHY
PLLs, these will be addressed in a follow-up.

Bspec: 49204

References: HSDES#22010772725
References: HSDES#14011861142
Reported-and-tested-by: Khaled Almahallawy <khaled.almahallawy@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Khaled Almahallawy <khaled.almahallawy@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200629185848.20550-1-imre.deak@intel.com
2020-07-01 15:39:00 +03:00
..
drm drm/i915/tgl+: Fix TBT DPLL fractional divider for 38.4MHz ref clock 2020-07-01 15:39:00 +03:00
host1x gpu: host1x: Use SMMU on Tegra124 and Tegra210 2020-04-28 11:44:07 +02:00
ipu-v3
trace gpu/trace: add a gpu total memory usage tracepoint 2020-03-03 17:52:41 -05:00
vga
Makefile gpu/trace: add a gpu total memory usage tracepoint 2020-03-03 17:52:41 -05:00