[PATCH] drm/amd/display: use div_s64() for 64-bit division

[Arnd Bergmann]

From: Arnd Bergmann <arnd@xxxxxxxx>

The open-coded 64-bit division causes a link error on 32-bit
machines:

ERROR: modpost: "__udivdi3" [drivers/gpu/drm/amd/amdgpu/amdgpu.ko] undefined!
ERROR: modpost: "__divdi3" [drivers/gpu/drm/amd/amdgpu/amdgpu.ko] undefined!

Use the div_s64() to perform the division here. One of them was an
unsigned division originally, but it looks like signed division was
intended, so use that to consistently allow a negative delay.

Fixes: ea7154d8d9fb ("drm/amd/display: Update dcn30_apply_idle_power_optimizations() code")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
 drivers/gpu/drm/amd/display/dc/dcn30/dcn30_hwseq.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_hwseq.c b/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_hwseq.c
index dff83c6a142a..a133e399e76d 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_hwseq.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_hwseq.c
@@ -772,8 +772,8 @@ bool dcn30_apply_idle_power_optimizations(struct dc *dc, bool enable)
 							cursor_cache_enable ? &cursor_attr : NULL)) {
 				unsigned int v_total = stream->adjust.v_total_max ?
 						stream->adjust.v_total_max : stream->timing.v_total;
-				unsigned int refresh_hz = (unsigned long long) stream->timing.pix_clk_100hz *
-						100LL /	(v_total * stream->timing.h_total);
+				unsigned int refresh_hz = div_s64((unsigned long long) stream->timing.pix_clk_100hz *
+						100LL, v_total * stream->timing.h_total);
 
 				/*
 				 * one frame time in microsec:
@@ -800,8 +800,8 @@ bool dcn30_apply_idle_power_optimizations(struct dc *dc, bool enable)
 				unsigned int denom = refresh_hz * 6528;
 				unsigned int stutter_period = dc->current_state->perf_params.stutter_period_us;
 
-				tmr_delay = (((1000000LL + 2 * stutter_period * refresh_hz) *
-						(100LL + dc->debug.mall_additional_timer_percent) + denom - 1) /
+				tmr_delay = div_s64(((1000000LL + 2 * stutter_period * refresh_hz) *
+						(100LL + dc->debug.mall_additional_timer_percent) + denom - 1),
 						denom) - 64LL;
 
 				/* scale should be increased until it fits into 6 bits */
@@ -815,8 +815,8 @@ bool dcn30_apply_idle_power_optimizations(struct dc *dc, bool enable)
 					}
 
 					denom *= 2;
-					tmr_delay = (((1000000LL + 2 * stutter_period * refresh_hz) *
-							(100LL + dc->debug.mall_additional_timer_percent) + denom - 1) /
+					tmr_delay = div_s64(((1000000LL + 2 * stutter_period * refresh_hz) *
+							(100LL + dc->debug.mall_additional_timer_percent) + denom - 1),
 							denom) - 64LL;
 				}
 
-- 
2.29.2