From bf0d608b55d9b7f426031dfd9f08d9df36c94728 Mon Sep 17 00:00:00 2001 From: Jani Nikula Date: Tue, 26 Oct 2021 12:34:07 +0300 Subject: [PATCH] drm/i915/dp: fix integer overflow in 128b/132b data rate calculation MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The intermediate value 1000000 * 10 * 9671 overflows 32 bits, so force promotion to a bigger type. From the logs: [drm:intel_dp_compute_config [i915]] DP link rate required 3657063 available -580783288 v2: Use mul_u32_u32() (Ville) Fixes: 48efd014f0ea ("drm/i915/dp: add max data rate calculation for UHBR rates") Cc: Manasi Navare Cc: Ville Syrjälä Reviewed-by: Ville Syrjälä Signed-off-by: Jani Nikula Link: https://patchwork.freedesktop.org/patch/msgid/20211026093407.11381-1-jani.nikula@intel.com --- drivers/gpu/drm/i915/display/intel_dp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index f5dc212..537c689 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -352,7 +352,7 @@ intel_dp_max_data_rate(int max_link_rate, int max_lanes) */ int max_link_rate_kbps = max_link_rate * 10; - max_link_rate_kbps = DIV_ROUND_CLOSEST_ULL(max_link_rate_kbps * 9671, 10000); + max_link_rate_kbps = DIV_ROUND_CLOSEST_ULL(mul_u32_u32(max_link_rate_kbps, 9671), 10000); max_link_rate = max_link_rate_kbps / 8; } -- 2.7.4