From: Alex Hung <alex.hung@amd.com>
Date: Mon, 3 Apr 2023 09:45:41 +0000 (+0800)
Subject: drm/amd/display: fix a divided-by-zero error
X-Git-Tag: v6.1.28~526
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=e43cf7abece2efaebe0a757909d258212d01c404;p=users%2Fdwmw2%2Flinux.git

drm/amd/display: fix a divided-by-zero error

[ Upstream commit 0b5dfe12755f87ec014bb4cc1930485026167430 ]

[Why & How]

timing.dsc_cfg.num_slices_v can be zero and it is necessary to check
before using it.

This fixes the error "divide error: 0000 [#1] PREEMPT SMP NOPTI".

Reviewed-by: Aurabindo Pillai <Aurabindo.Pillai@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/drivers/gpu/drm/amd/display/modules/power/power_helpers.c b/drivers/gpu/drm/amd/display/modules/power/power_helpers.c
index 01fc6a368d2e3..9edd39322c822 100644
--- a/drivers/gpu/drm/amd/display/modules/power/power_helpers.c
+++ b/drivers/gpu/drm/amd/display/modules/power/power_helpers.c
@@ -924,6 +924,10 @@ bool psr_su_set_y_granularity(struct dc *dc, struct dc_link *link,
 
 	pic_height = stream->timing.v_addressable +
 		stream->timing.v_border_top + stream->timing.v_border_bottom;
+
+	if (stream->timing.dsc_cfg.num_slices_v == 0)
+		return false;
+
 	slice_height = pic_height / stream->timing.dsc_cfg.num_slices_v;
 
 	if (slice_height) {