Re: [PATCH v2] drm/xe/pcode: Convert unsupported commands to debug level

[Raag Jadav <raag.jadav@intel.com>]

On Fri, Nov 07, 2025 at 03:16:18PM +0200, Ville Syrjälä wrote:
> On Fri, Nov 07, 2025 at 06:03:28AM -0600, Lucas De Marchi wrote:
> > On Fri, Nov 07, 2025 at 11:26:11AM +0530, Raag Jadav wrote:
> > > If the device is running older pcode firmware, it is possible that newer
> > > mailbox commands are not supported by it. The respective functionality
> > > isn't useful in that case but neither is error logging, since it doesn't
> > > particularly signify anything wrong with pcode firmware or device as a
> > > whole. This is useful in cases where we want to make a decision on driver
> > > functionality based on pcode return codes and a bit simpler design choice
> > > compared to other solutions like checking pcode firmware version, which
> > > comes with additional complexity of binding every single command to a
> > > specific version and deems pcode commands useless in case driver fails to
> > > obtain it for reasons unrelated to pcode.
> > 
> > yeah.. I don't think we should regress the support in new kernel
> > versions and require users to update their IFWI. However dropping the
> > error message here also makes it harder to find cases in which we are
> > indeed using a wrong command.
> > 
> > I'd say to decide on err vs dbg based on CONFIG_DRM_XE_DEBUG so
> > developers can still see the error and take the right action.
> 
> I think the caller should decide this. If it's explicitly probing
> for something that may or may not exist then use  dbg(), otherwise
> use err().

I like the idea. What I'm afraid is that once we open that door it'll
probably start getting abused.

So rather we can check if we're really *in* probe()? Wait for a v3.

Raag