AMD-GFX Archive on lore.kernel.org
 help / color / Atom feed
From: Arnd Bergmann <arnd@kernel.org>
To: "Harry Wentland" <harry.wentland@amd.com>,
	"Leo Li" <sunpeng.li@amd.com>,
	"Alex Deucher" <alexander.deucher@amd.com>,
	"Christian König" <christian.koenig@amd.com>,
	"David Airlie" <airlied@linux.ie>,
	"Daniel Vetter" <daniel@ffwll.ch>,
	"Joshua Aberback" <joshua.aberback@amd.com>,
	"Bhawanpreet Lakha" <Bhawanpreet.Lakha@amd.com>,
	"Nicholas Kazlauskas" <nicholas.kazlauskas@amd.com>
Cc: Arnd Bergmann <arnd@arndb.de>,
	Wesley Chalmers <Wesley.Chalmers@amd.com>,
	Qingqing Zhuo <qingqing.zhuo@amd.com>,
	Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>,
	linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org,
	dri-devel@lists.freedesktop.org, Jacky Liao <ziyu.liao@amd.com>,
	Martin Leung <martin.leung@amd.com>
Subject: [PATCH] drm/amd/display: use div_s64() for 64-bit division
Date: Mon, 25 Jan 2021 12:39:55 +0100
Message-ID: <20210125114012.2480845-1-arnd@kernel.org> (raw)

From: Arnd Bergmann <arnd@arndb.de>

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@arndb.de>
---
 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

_______________________________________________
amd-gfx mailing list
amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx

             reply index

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-25 11:39 Arnd Bergmann [this message]
2021-01-25 12:51 ` Chen, Guchun
2021-01-25 13:10   ` Arnd Bergmann

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210125114012.2480845-1-arnd@kernel.org \
    --to=arnd@kernel.org \
    --cc=Bhawanpreet.Lakha@amd.com \
    --cc=Rodrigo.Siqueira@amd.com \
    --cc=Wesley.Chalmers@amd.com \
    --cc=airlied@linux.ie \
    --cc=alexander.deucher@amd.com \
    --cc=amd-gfx@lists.freedesktop.org \
    --cc=arnd@arndb.de \
    --cc=christian.koenig@amd.com \
    --cc=daniel@ffwll.ch \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=harry.wentland@amd.com \
    --cc=joshua.aberback@amd.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=martin.leung@amd.com \
    --cc=nicholas.kazlauskas@amd.com \
    --cc=qingqing.zhuo@amd.com \
    --cc=sunpeng.li@amd.com \
    --cc=ziyu.liao@amd.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

AMD-GFX Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/amd-gfx/0 amd-gfx/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 amd-gfx amd-gfx/ https://lore.kernel.org/amd-gfx \
		amd-gfx@lists.freedesktop.org
	public-inbox-index amd-gfx

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.freedesktop.lists.amd-gfx


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git