linux/drivers/gpu
Venkateswara Rao Mandela c618a3a93b drm/omap: Implement workaround for DRA7 errata ID:i932
Description of DRA7 Errata i932:

In rare circumstances DPLL_VIDEO1 and DPLL_VIDEO2 PLL's may not lock on
the first attempt during DSS initialization. When this occurs, a
subsequent attempt to relock the PLL will result in PLL successfully
locking.

This patch does the following as per the errata recommendation:

- retries locking the PLL upto 20 times.

- The time to wait for a PLL lock set to 1000 REFCLK cycles. We use
usleep_range to wait for 1000 REFCLK cycles in the us range. This tight
constraint is imposed as a lock later than 1000 REFCLK cycles may have
high jitter.

- Criteria for PLL lock is extended from check on just the PLL_LOCK bit
to check on 6 PLL_STATUS bits.

Silicon Versions Impacted:
DRA71, DRA72, DRA74, DRA76 - All silicon revisions
AM57x - All silicon revisions

OMAP4/5 are not impacted by this errata

Signed-off-by: Venkateswara Rao Mandela <venkat.mandela@ti.com>
[tomi.valkeinen@ti.com: ported to v4.14]
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
2018-06-28 13:41:05 +03:00
..
drm drm/omap: Implement workaround for DRA7 errata ID:i932 2018-06-28 13:41:05 +03:00
host1x drm for v4.18-rc1 2018-06-06 08:16:33 -07:00
ipu-v3 gpu: ipu-v3: prg: avoid possible array underflow 2018-03-15 17:52:08 +01:00
vga docs: Fix some broken references 2018-06-15 18:10:01 -03:00
Makefile