diff options
Diffstat (limited to 'meta-amd-bsp/recipes-kernel/linux/linux-yocto-4.19.8/2846-drm-amd-display-avoid-64-bit-division.patch')
| -rw-r--r-- | meta-amd-bsp/recipes-kernel/linux/linux-yocto-4.19.8/2846-drm-amd-display-avoid-64-bit-division.patch | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/meta-amd-bsp/recipes-kernel/linux/linux-yocto-4.19.8/2846-drm-amd-display-avoid-64-bit-division.patch b/meta-amd-bsp/recipes-kernel/linux/linux-yocto-4.19.8/2846-drm-amd-display-avoid-64-bit-division.patch new file mode 100644 index 00000000..315cc0f5 --- /dev/null +++ b/meta-amd-bsp/recipes-kernel/linux/linux-yocto-4.19.8/2846-drm-amd-display-avoid-64-bit-division.patch @@ -0,0 +1,58 @@ +From 3dcceb5743dacdd413e0981b2f20747b30ac9353 Mon Sep 17 00:00:00 2001 +From: Arnd Bergmann <arnd@arndb.de> +Date: Mon, 8 Jul 2019 15:52:08 +0200 +Subject: [PATCH 2846/2940] drm/amd/display: avoid 64-bit division + +On 32-bit architectures, dividing a 64-bit integer in the kernel +leads to a link error: + +ERROR: "__udivdi3" [drivers/gpu/drm/amd/amdgpu/amdgpu.ko] undefined! +ERROR: "__divdi3" [drivers/gpu/drm/amd/amdgpu/amdgpu.ko] undefined! + +Change the two recently introduced instances to a multiply+shift +operation that is also much cheaper on 32-bit architectures. +We can do that here, since both of them are really 32-bit numbers +that change a few percent. + +Fixes: bedbbe6af4be ("drm/amd/display: Move link functions from dc to dc_link") +Fixes: f18bc4e53ad6 ("drm/amd/display: update calculated bounding box logic for NV") +Acked-by: Slava Abramov <slava.abramov@amd.com> +Tested-by: Slava Abramov <slava.abramov@amd.com> +Signed-off-by: Arnd Bergmann <arnd@arndb.de> +Signed-off-by: Alex Deucher <alexander.deucher@amd.com> +--- + drivers/gpu/drm/amd/display/dc/core/dc_link.c | 4 ++-- + drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c | 2 +- + 2 files changed, 3 insertions(+), 3 deletions(-) + +diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link.c b/drivers/gpu/drm/amd/display/dc/core/dc_link.c +index e94d65ad0d90..dbc925273512 100644 +--- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c ++++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c +@@ -3070,8 +3070,8 @@ uint32_t dc_link_bandwidth_kbps( + * but the difference is minimal and is in a safe direction, + * which all works well around potential ambiguity of DP 1.4a spec. + */ +- long long fec_link_bw_kbps = link_bw_kbps * 970LL; +- link_bw_kbps = (uint32_t)(fec_link_bw_kbps / 1000LL); ++ link_bw_kbps = mul_u64_u32_shr(BIT_ULL(32) * 970LL / 1000, ++ link_bw_kbps, 32); + } + #endif + +diff --git a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c +index 385a36f51f43..14920c180836 100644 +--- a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c ++++ b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c +@@ -2655,7 +2655,7 @@ static void update_bounding_box(struct dc *dc, struct _vcs_dpi_soc_bounding_box_ + calculated_states[i].dram_speed_mts = uclk_states[i] * 16 / 1000; + + // FCLK:UCLK ratio is 1.08 +- min_fclk_required_by_uclk = ((unsigned long long)uclk_states[i]) * 1080 / 1000000; ++ min_fclk_required_by_uclk = mul_u64_u32_shr(BIT_ULL(32) * 1080 / 1000000, uclk_states[i], 32); + + calculated_states[i].fabricclk_mhz = (min_fclk_required_by_uclk < min_dcfclk) ? + min_dcfclk : min_fclk_required_by_uclk; +-- +2.17.1 + |