[Intel-gfx] [PATCH v2 07/12] drm/i915/icl: Use revid->stepping tables

[Lucas De Marchi]

On Fri, Jul 09, 2021 at 08:37:19PM -0700, Matt Roper wrote:
>Switch ICL to use a revid->stepping table as we're trying to do on all
>platforms going forward.  While we're at it, let's include some
>additional steppings that have popped up, even if we don't yet have any
>workarounds tied to those steppings (we probably need to audit our
>workaround list soon to see if any of the bounds have moved or if new
>workarounds have appeared).
>
>Note that the current bspec table is missing information about how to
>map PCI revision ID to GT/display steppings; it only provides an SoC
>stepping.  The mapping to GT/display steppings (which aren't always the
>same as the SoC stepping) used to be in the bspec, but was apparently
>dropped during an update in Nov 2019; I've made my changes here based on
>an older bspec snapshot that still had the necessary information.  We've
>requested that the missing information be restored.
>
>I'm only including the production revids in the table here since we're
>past the point at which we usually stop trying to support pre-production
>hardware.  An appropriate check is added to
>intel_detect_preproduction_hw() to print an error and taint the kernel
>just in case someone still tries to load the driver on old
>pre-production hardware.
>
>v2:
> - Drop pre-production steppings and add error/taint at startup when
>   loading on pre-production hardware.

oh... I forgot to send my review. Here is the commend I had:

It seems we are not actually dropping the WAs. We have several applying
only to A0 or A0/B0. From your first paragraph, is the intention to do
an audit of the WA ranges later?  Because we are currently running
without applying those WAs, so those are effectively dead code.

Lucas De Marchi