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

[Matt Roper]

On Tue, Jul 13, 2021 at 12:57:07PM -0700, Lucas De Marchi wrote:
> 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.

The actual dropping of workarounds for pre-production steppings happens
in patch #12.  But a more in-depth audit will be done in the future.


Matt

> 
> Lucas De Marchi

-- 
Matt Roper
Graphics Software Engineer
VTT-OSGC Platform Enablement
Intel Corporation
(916) 356-2795