Re: [PATCH] drm/xe/xe3: Apply wa_14024997852

["Tapani Pälli" <tapani.palli@intel.com>]

On 10/25/25 02:52, Matt Roper wrote:
> On Thu, Oct 23, 2025 at 07:40:41AM +0300, Tapani Pälli wrote:
>> Whitelist registers needed for userspace to control autostrip on xe3.
>>
>> Signed-off-by: Tapani Pälli <tapani.palli@intel.com>
>> ---
>>   drivers/gpu/drm/xe/xe_reg_whitelist.c | 7 +++++++
>>   1 file changed, 7 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/xe/xe_reg_whitelist.c b/drivers/gpu/drm/xe/xe_reg_whitelist.c
>> index 690bc327a363..fab56673153b 100644
>> --- a/drivers/gpu/drm/xe/xe_reg_whitelist.c
>> +++ b/drivers/gpu/drm/xe/xe_reg_whitelist.c
>> @@ -89,6 +89,13 @@ static const struct xe_rtp_entry_sr register_whitelist[] = {
>>   				   RING_FORCE_TO_NONPRIV_ACCESS_RD |
>>   				   RING_FORCE_TO_NONPRIV_RANGE_4))
>>   	},
>> +	{ XE_RTP_NAME("14024997852"),
>> +	  XE_RTP_RULES(GRAPHICS_VERSION(3500), ENGINE_CLASS(RENDER)),
> We don't have any platforms with an IP version of exactly 35.00.  If you
> were trying to whitelist this for everything Xe3p and beyond, you could
> use GRAPHICS_VERSION_RANGE with an undefined upper bound, but generally
> we avoid doing that for whitelists because future platforms/IPs might
> not need this workaround anymore, but some new setting with security
> implications could get added to the register in the future and we
> wouldn't want to accidentally give userspace access on those future
> platforms due to an unbounded range on the whitelist entry.
>
> The only Xe3p platform we have on drm-tip at the moment is Xe3p_XPC
> (version 35.11), but as far as I can see, Wa_14024997852 doesn't apply
> there (and in fact that IP doesn't even have a render engine).  This
> workaround _does_ apply to various Xe3 platform though (with versions
> ranging from 30.00 to 30.05) and we don't seem to have those whitelisted
> in the KMD yet.  Your patch here has an "xe3" prefix, so are those the
> versions you actually intended to target?

Argh yes, the intention was indeed to target "3000", not "3500". Will 
fix this.

For me it looks like this WA is for whole the xe3 so I'm assuming 
GRAPHICS_VERSION_RANGE or GRAPHICS_STEP is not necessary for this WA.


>
> Matt
>
>> +	  XE_RTP_ACTIONS(WHITELIST(FF_MODE,
>> +				   RING_FORCE_TO_NONPRIV_ACCESS_RW),
>> +			 WHITELIST(VFLSKPD,
>> +				   RING_FORCE_TO_NONPRIV_ACCESS_RW))
>> +	},
>>   };
>>   
>>   static void whitelist_apply_to_hwe(struct xe_hw_engine *hwe)
>> -- 
>> 2.51.0
>>