From: Ankit Nautiyal Date: Wed, 18 Jun 2025 13:09:50 +0000 (+0530) Subject: drm/i915/snps_hdmi_pll: Fix 64-bit divisor truncation by using div64_u64 X-Git-Tag: v6.16-rc4~14^2~2^2~2 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=9205999e9f13a07cb29d5a8836c25afdca186007;p=thirdparty%2Fkernel%2Flinux.git drm/i915/snps_hdmi_pll: Fix 64-bit divisor truncation by using div64_u64 DIV_ROUND_CLOSEST_ULL uses do_div(), which expects a 32-bit divisor. When passing a 64-bit constant like CURVE2_MULTIPLIER, the value is silently truncated to u32, potentially leading to incorrect results on large divisors. Replace DIV_ROUND_CLOSEST_ULL with DIV64_U64_ROUND_CLOSEST which correctly handles full 64-bit division. v2: Use DIV64_U64_ROUND_CLOSEST instead of div64_u64 macro. (Jani) Fixes: 5947642004bf ("drm/i915/display: Add support for SNPS PHY HDMI PLL algorithm for DG2") Reported-by: Vas Novikov Closes: https://lore.kernel.org/all/8d7c7958-9558-4c8a-a81a-e9310f2d8852@gmail.com/ Cc: Ankit Nautiyal Cc: Suraj Kandpal Cc: Jani Nikula Cc: Vas Novikov Cc: stable@vger.kernel.org # v6.15+ Reviewed-by: Jani Nikula Signed-off-by: Ankit Nautiyal Link: https://lore.kernel.org/r/20250618130951.1596587-2-ankit.k.nautiyal@intel.com (cherry picked from commit b300a175a11e6a934d728317dc39787723cc7917) Signed-off-by: Joonas Lahtinen --- diff --git a/drivers/gpu/drm/i915/display/intel_snps_hdmi_pll.c b/drivers/gpu/drm/i915/display/intel_snps_hdmi_pll.c index 74bb3bedf30f5..5111bdc3075b5 100644 --- a/drivers/gpu/drm/i915/display/intel_snps_hdmi_pll.c +++ b/drivers/gpu/drm/i915/display/intel_snps_hdmi_pll.c @@ -103,8 +103,8 @@ static void get_ana_cp_int_prop(u64 vco_clk, DIV_ROUND_DOWN_ULL(curve_1_interpolated, CURVE0_MULTIPLIER))); ana_cp_int_temp = - DIV_ROUND_CLOSEST_ULL(DIV_ROUND_DOWN_ULL(adjusted_vco_clk1, curve_2_scaled1), - CURVE2_MULTIPLIER); + DIV64_U64_ROUND_CLOSEST(DIV_ROUND_DOWN_ULL(adjusted_vco_clk1, curve_2_scaled1), + CURVE2_MULTIPLIER); *ana_cp_int = max(1, min(ana_cp_int_temp, 127));