Wa_15015404425 only needs to be applied on PTL platforms with an A step
compute die. There is no way to map PCI revid to the compute die
stepping. The easiest way to figure out compute die stepping our end is
to map the media IP's stepping to the compute die. For PTL, compute die
has an A stepping if and only if the media IP's stepping is also A-step
(This relationship is determined on a per platform basis and just
happens to be this way on PTL).
In addition this workaround is a chicken-and-egg problem. Wa_15015404425
requires that all register reads be preceded by four dummy MMIO writes
(including during early driver init and even pre-OS firmware). The
driver needs to perform some MMIO reads during init which include the
GMD_ID register that contains the Media IPs stepping. To handle this in
the safest manner assume the workaround applies to all of PTL during
driver probe and deactivate the workaround after.
The overall solution becomes a set of two workarounds:
* 15015404425 - a Device OOB workaround that's always active for PTL
* 15015404425_disable - a GT OOB workaround that applies to PTL
platfroms with a B0 or later stepping
The first of these workarounds issues dummy MMIO writes we do when
reading registers. The second guards logic that disables the first once
we have the necessary information later in the probe process.
v2: rename SoC to device, avoid null pointer dereference, update commit
message.
v3: rebase
v5: move disable check into xe_device_probe to avoid linking in xe_wa
into xe_pci, reword commit message
v6: squash extension and b0 support into 1 patch
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Matt Atwood <matthew.s.atwood@intel.com>
Link: https://lore.kernel.org/r/20250709221605.172516-7-matthew.s.atwood@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Move Wa_15015404425 to use the new implemented OOB macro XE_DEVICE_WA()
v2: rename from SoC to Device
v5: move workaround call back into the flush call
v6: remove redundant commenting
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Matt Atwood <matthew.s.atwood@intel.com>
Link: https://lore.kernel.org/r/20250709221605.172516-6-matthew.s.atwood@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
There are some workarounds that must be appplied before gt init,
wa_15015404425 for example. Instead of sprinking them conditionally
throughout the driver as we did for i915 generate an oob.rules file
reusing the RTP infrastructure to make these easier to track.
v2: rename xe_soc_wa to xe_device_wa
v5: derive prefix from argument rather than hard coding the values.
v6: split out xe_gen-wa_oob changes
Signed-off-by: Matt Atwood <matthew.s.atwood@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://lore.kernel.org/r/20250709221605.172516-3-matthew.s.atwood@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
