The RC6 VIDS has a linear ramp starting at 250mv, which means any values below 250 are invalid. The old buggy macros tried to adjust for this to be more flexible, but there is no need. As Dan pointed out the ENCODE only ever has one value. The only invalid value for decode is an input of 0 which means something is really wonky, and the cases where DECODE are used either don't matter (debug values), or would be implicitly correct (the check for less than 450).
This patch makes simpler, easier to read macros which are actually correct. Maybe this patch can actually fix some bugs now.
Thanks to Dan for catching this. /me hides
Cc: stable@kernel.org Reported-by: Dan Carpenter dan.carpenter@oracle.com Signed-off-by: Ben Widawsky ben@bwidawsk.net --- drivers/gpu/drm/i915/i915_reg.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index 59afb7e..2a754e2 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -4280,8 +4280,8 @@ #define GEN6_PCODE_READ_MIN_FREQ_TABLE 0x9 #define GEN6_PCODE_WRITE_RC6VIDS 0x4 #define GEN6_PCODE_READ_RC6VIDS 0x5 -#define GEN6_ENCODE_RC6_VID(mv) (((mv) / 5) - 245) < 0 ?: 0 -#define GEN6_DECODE_RC6_VID(vids) (((vids) * 5) > 0 ? ((vids) * 5) + 245 : 0) +#define GEN6_ENCODE_RC6_VID(mv) (((mv) - 245) / 5) +#define GEN6_DECODE_RC6_VID(vids) (((vids) * 5) + 245) #define GEN6_PCODE_DATA 0x138128 #define GEN6_PCODE_FREQ_IA_RATIO_SHIFT 8