Re: [PATCH] drm/xe/mmio: Fix xe_mmio_wait32() to honor delay/sleep maximums

[Jani Nikula <jani.nikula@intel.com>]

On Tue, 15 Sep 2026, "Teres Alexis, Alan Previn" <alan.previn.teres.alexis@intel.com> wrote:
> On Tue, 2026-09-15 at 10:34 +0300, Nikula, Jani wrote:
>> On Mon, 14 Sep 2026, Alan Previn <alan.previn.teres.alexis@intel.com> wrote:
> alan:snip
>> >  int xe_mmio_wait32(struct xe_mmio *mmio, struct xe_reg reg, u32 mask, u32 val, u32 timeout_us,
>> > -		   u32 *out_val, bool atomic)
>> > +		   u32 *out_val)
>> >  {
>> > -	return __xe_mmio_wait32(mmio, reg, mask, val, timeout_us, out_val, atomic, true);
>> > +	u32 read;
>> > +	int ret;
>> > +
>> > +	ret = poll_timeout_us(read = xe_mmio_read32(mmio, reg), (read & mask) == val,
>> > +			      10, timeout_us, false);
>> 
>> You probably do need to let the callers pass in the wait too. 10 us wait
>> with a long timeout is going to be pretty bad.
>> 
>> 
> alan: okay - perhaps i can make every caller pass in a polling-wait thats a fraction of their wait time.
> (as a starting point since i dont know what's the expected behavior of every caller).
> so perhaps something like "timeout_us << 4" (i.e. 1/16th) but pass in 10 us if its anything smaller than that
> (i.e. smaller than 16 usec).

I think you need to talk to the xe maintainers, really.

BR,
Jani.


-- 
Jani Nikula, Intel