drm/i915/dram: Fix ICL DIMM_S decoding

Browse source

Unfortunately the MAD_DIMM DIMM_S and DIMM_L bits on ICL are
not idential, so we are currently decoding DIMM_S incorrectly.

Fix the problem by defining the DIMM_S and DIMM_L bits separately.
And for consistency do that same for SKL, even though there the
bits do match between the two DIMMs. The result is rather
repetitive in places, but I didn't feel like obfuscatign things
with cpp macros/etc.

Broken decoding on Dell XPS 13 7390 2-in-1:
 CH0 DIMM L size: 32 Gb, width: X16, ranks: 2, 16Gb+ DIMMs: no
 CH0 DIMM S size: 32 Gb, width: X32, ranks: 3, 16Gb+ DIMMs: no
 CH0 ranks: 2, 16Gb+ DIMMs: no
 CH1 DIMM L size: 32 Gb, width: X16, ranks: 2, 16Gb+ DIMMs: no
 CH1 DIMM S size: 32 Gb, width: X32, ranks: 3, 16Gb+ DIMMs: no
 CH1 ranks: 2, 16Gb+ DIMMs: no
 Memory configuration is symmetric? no

Fixed decoding on Dell XPS 13 7390 2-in-1:
 CH0 DIMM L size: 32 Gb, width: X16, ranks: 2, 16Gb+ DIMMs: no
 CH0 DIMM S size: 32 Gb, width: X16, ranks: 2, 16Gb+ DIMMs: no
 CH0 ranks: 2, 16Gb+ DIMMs: no
 CH1 DIMM L size: 32 Gb, width: X16, ranks: 2, 16Gb+ DIMMs: no
 CH1 DIMM S size: 32 Gb, width: X16, ranks: 2, 16Gb+ DIMMs: no
 CH1 ranks: 2, 16Gb+ DIMMs: no
 Memory configuration is symmetric? yes

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20251029204215.12292-4-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>

...

This commit is contained in:

Ville Syrjälä 2025-10-29 22:42:15 +02:00

parent 8c171a9b8c

commit 7e2d785354

2 changed files with 155 additions and 64 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

53

drivers/gpu/drm/i915/intel_mchbar_regs.h

View file

166

drivers/gpu/drm/i915/soc/intel_dram.c

View file