Commit 6f1e094f authored by Chaitanya Kumar Borah's avatar Chaitanya Kumar Borah Committed by Jani Nikula
Browse files

drm/i915/color: Preserve sign bit when int_bits is Zero 



When int_bits == 0, we lose the sign bit when we do the range check
and apply the mask.

Fix this by ensuring a minimum of one integer bit, which guarantees space
for the sign bit in fully fractional representations (e.g. S0.12)

Reviewed-by: default avatarSuraj Kandpal <suraj.kandpal@intel.com>
Signed-off-by: default avatarChaitanya Kumar Borah <chaitanya.kumar.borah@intel.com>
Signed-off-by: default avatarUma Shankar <uma.shankar@intel.com>
Link: https://patch.msgid.link/20251203085211.3663374-7-uma.shankar@intel.com


Signed-off-by: default avatarJani Nikula <jani.nikula@intel.com>
parent a78f1b6b

drivers/gpu/drm/i915/display/intel_color.c

+2 −0
Original line number Diff line number Diff line
@@ -613,6 +613,8 @@ static u16 ctm_to_twos_complement(u64 coeff, int int_bits, int frac_bits) 
	if (CTM_COEFF_NEGATIVE(coeff))

		c = -c;



	int_bits = max(int_bits, 1);



	c = clamp(c, -(s64)BIT(int_bits + frac_bits - 1),

		  (s64)(BIT(int_bits + frac_bits - 1) - 1));