On 08/08/2024 13:24, Mary Guillemard wrote:
As it stands, this query has nothing to do with the actual GPU so
doesn't really belong here.
It'd be more valuable, and can maybe give better calibration results
than querying the system timestamp separately in userspace, if you
reported all of:
* the system timer value
* the system timer frequency
* the GPU timer value
* the GPU timer frequency (because it _could_ be different in some systems)
* the GPU timer offset
I see, I missed those registers... I will also fix this on my v2 of my Panfrost series.
From my understanding, the GPU timer frequency doesn't have a register
so I suppose it would be wired to cntfrq_el0 if CONFIG_ARM_ARCH_TIMER is
set, am I correct?
Barring any HW errata, yes, that's the frequency the GPU timer should
tick at, too.
Thanks for the review,
Mary
--
Mihail Atanassov <mihail.atanassov@xxxxxxx>
