On 10/18/2023 3:00 PM, Andi Shyti wrote:
Hi Nirmoy,
gen8_ggtt_invalidate() is only needed for limited set of platforms
where GGTT is mapped as WC. This was added as way to fix WC based GGTT in
commit 0f9b91c754b7 ("drm/i915: flush system agent TLBs on SNB") and
there are no reference in HW docs that forces us to use this on non-WC
backed GGTT.
This can also cause unwanted side-effects on XE_HP platforms where
GFX_FLSH_CNTL_GEN6 is not valid anymore.
v2: Add a func to detect wc ggtt detection (Ville)
v3: Improve commit log and add reference commit (Daniel)
Fixes: d2eae8e98d59 ("drm/i915/dg2: Drop force_probe requirement")
I'm wondering if this is the right Fixes, though. Should this
rather be:
Fixes: 6266992cf105 ("drm/i915/gt: remove GRAPHICS_VER == 10")
Hard to find a real Fixes for this. I just want to backport this to dg2
where we can have unwanted side-effects.
yes, this piece of code has moved around enough so to make it
diffuclt to track its origin.
I think the one I found should be the correct one,
That just removes a graphics ver, not related to WC GGTT map or XE_HP.
but the dg2
force probe removeal can also become a placeholder for DG2 fixes.
Yes, I have no better ideas too.
Regards,
Nirmoy
I won't complain.
Andi
