Commit 54d4dee9f89e for kernel
commit 54d4dee9f89e1dac1a6c2618de0bb2e3f35cc2f0
Author: yanglinlin <yanglinlin@kylinos.cn>
Date: Mon Jul 13 11:12:28 2026 +0800
drm/amd/display: fix __udivdi3 link error
When compiling the AMDGPU display driver for 32-bit architectures,
the linker reports undefined reference to `__udivdi3` in functions
get_dp_dto_frequency_100hz() and dcn401_get_dp_dto_frequency_100hz().
This is because the code uses 64-bit division (/) on 32-bit systems,
which GCC cannot handle directly and instead tries to call the missing
__udivdi3 helper function.
Replace the raw division with div_u64(), the kernel's standard 64-bit
division helper, to avoid the link error.
Signed-off-by: Linlin Yang <yanglinlin@kylinos.cn>
Reported-by: k2ci <kernel-bot@kylinos.cn>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 0421fc6ab3a8514e99156ff3c2cee13ee9af3fa7)
Cc: stable@vger.kernel.org
diff --git a/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c b/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c
index 7c293917e6fd..ecb8493ec523 100644
--- a/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c
+++ b/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c
@@ -1229,9 +1229,9 @@ static bool get_dp_dto_frequency_100hz(
*/
modulo_hz = REG_READ(MODULO[inst]);
if (modulo_hz) {
- temp = div_u64((uint64_t)clock_hz * dp_dto_ref_khz * 10, modulo_hz);
- ASSERT(temp / 100 <= 0xFFFFFFFFUL);
- *pixel_clk_100hz = (unsigned int)(temp / 100);
+ temp = clock_hz * dp_dto_ref_khz * 10;
+ ASSERT(temp <= UINT_MAX * modulo_hz * 100ULL);
+ *pixel_clk_100hz = div_u64(temp, modulo_hz * 100);
} else
*pixel_clk_100hz = 0;
} else {
@@ -1285,13 +1285,12 @@ static bool dcn401_get_dp_dto_frequency_100hz(const struct clock_source *clock_s
* - target pix_clk_hz = (DPDTO INTEGER * DPDTO MODULO + DPDTO PHASE)
*/
temp = (unsigned long long)dp_dto_integer * modulo_hz + phase_hz;
-
- if (temp / 100 > 0xFFFFFFFFUL) {
+ if (temp > (UINT_MAX * 100ULL)) {
/* pixel rate 100hz should never be this high, if it is, throw an assert and return 0 */
BREAK_TO_DEBUGGER();
*pixel_clk_100hz = 0;
} else {
- *pixel_clk_100hz = (unsigned int)(temp / 100);
+ *pixel_clk_100hz = div_u64(temp, 100);
}
return true;