[PATCH] drm/amd/display: fix 64-bit integer division
Arnd Bergmann
arnd at kernel.org
Thu Feb 25 14:33:10 UTC 2021
From: Arnd Bergmann <arnd at arndb.de>
The new display synchronization code caused a regression
on all 32-bit architectures:
ld.lld: error: undefined symbol: __aeabi_uldivmod
>>> referenced by dce_clock_source.c
>>> gpu/drm/amd/display/dc/dce/dce_clock_source.o:(get_pixel_clk_frequency_100hz) in archive drivers/built-in.a
ld.lld: error: undefined symbol: __aeabi_ldivmod
>>> referenced by dc_resource.c
>>> gpu/drm/amd/display/dc/core/dc_resource.o:(resource_are_vblanks_synchronizable) in archive drivers/built-in.a
>>> referenced by dc_resource.c
>>> gpu/drm/amd/display/dc/core/dc_resource.o:(resource_are_vblanks_synchronizable) in archive drivers/built-in.a
>>> referenced by dc_resource.c
>>> gpu/drm/amd/display/dc/core/dc_resource.o:(resource_are_vblanks_synchronizable) in archive drivers/built-in.a
This is not a fast path, so the use of an explicit div_u64/div_s64
seems appropriate.
Fixes: 77a2b7265f20 ("drm/amd/display: Synchronize displays with different timings")
Signed-off-by: Arnd Bergmann <arnd at arndb.de>
---
drivers/gpu/drm/amd/display/dc/core/dc_resource.c | 12 ++++++------
.../gpu/drm/amd/display/dc/dce/dce_clock_source.c | 6 +++---
2 files changed, 9 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
index 0241c9d96d7a..49214c59c836 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
@@ -441,15 +441,15 @@ bool resource_are_vblanks_synchronizable(
if (stream2->timing.pix_clk_100hz*100/stream2->timing.h_total/
stream2->timing.v_total > 60)
return false;
- frame_time_diff = (int64_t)10000 *
+ frame_time_diff = div_s64(10000ll *
stream1->timing.h_total *
stream1->timing.v_total *
- stream2->timing.pix_clk_100hz /
- stream1->timing.pix_clk_100hz /
- stream2->timing.h_total /
- stream2->timing.v_total;
+ stream2->timing.pix_clk_100hz,
+ stream1->timing.pix_clk_100hz *
+ stream2->timing.h_total *
+ stream2->timing.v_total);
for (i = 0; i < rr_count; i++) {
- int64_t diff = (frame_time_diff * base60_refresh_rates[i]) / 10 - 10000;
+ int64_t diff = div_s64(frame_time_diff * base60_refresh_rates[i], 10) - 10000;
if (diff < 0)
diff = -diff;
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 6f47f9bab5ee..85ed6f2c9647 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
@@ -1013,9 +1013,9 @@ static bool get_pixel_clk_frequency_100hz(
* not be programmed equal to DPREFCLK
*/
modulo_hz = REG_READ(MODULO[inst]);
- *pixel_clk_khz = ((uint64_t)clock_hz*
- clock_source->ctx->dc->clk_mgr->dprefclk_khz*10)/
- modulo_hz;
+ *pixel_clk_khz = div_u64((uint64_t)clock_hz * 10 *
+ clock_source->ctx->dc->clk_mgr->dprefclk_khz,
+ modulo_hz);
} else {
/* NOTE: There is agreement with VBIOS here that MODULO is
* programmed equal to DPREFCLK, in which case PHASE will be
--
2.29.2
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