From: "Gustavo Kenji Mendonça Kaneko" <kaneko.dev@pm.me>
To: dri-devel@lists.freedesktop.org
Cc: liviu.dudau@arm.com, airlied@gmail.com, simona@ffwll.ch,
linux-kernel@vger.kernel.org,
"Gustavo Kenji Mendonça Kaneko" <kaneko.dev@pm.me>
Subject: [PATCH 1/2] drm/arm/malidp: fix ignored clk_prepare_enable() in runtime PM resume
Date: Sun, 31 May 2026 05:29:57 +0000 [thread overview]
Message-ID: <20260531052945.65117-1-kaneko.dev@pm.me> (raw)
malidp_runtime_pm_resume() calls clk_prepare_enable() three times
without checking the return value. If any clock fails to enable, the
driver silently proceeds with unclocked hardware, leading to undefined
behavior.
Use clk_bulk_prepare_enable() which atomically enables all clocks and
automatically rolls back successfully enabled clocks on failure. This
is consistent with how the suspend path already uses
clk_bulk_disable_unprepare() in malidp_runtime_pm_suspend().
This issue was found by code review without access to Mali DP hardware.
Signed-off-by: Gustavo Kenji Mendonça Kaneko <kaneko.dev@pm.me>
---
drivers/gpu/drm/arm/malidp_drv.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/arm/malidp_drv.c b/drivers/gpu/drm/arm/malidp_drv.c
index b765f6c9eea4..1e4336c3a2fa 100644
--- a/drivers/gpu/drm/arm/malidp_drv.c
+++ b/drivers/gpu/drm/arm/malidp_drv.c
@@ -689,10 +689,17 @@ static int malidp_runtime_pm_resume(struct device *dev)
struct drm_device *drm = dev_get_drvdata(dev);
struct malidp_drm *malidp = drm_to_malidp(drm);
struct malidp_hw_device *hwdev = malidp->dev;
+ struct clk_bulk_data clks[] = {
+ { .clk = hwdev->pclk },
+ { .clk = hwdev->aclk },
+ { .clk = hwdev->mclk },
+ };
+ int err;
+
+ err = clk_bulk_prepare_enable(ARRAY_SIZE(clks), clks);
+ if (err)
+ return err;
- clk_prepare_enable(hwdev->pclk);
- clk_prepare_enable(hwdev->aclk);
- clk_prepare_enable(hwdev->mclk);
hwdev->pm_suspended = false;
malidp_de_irq_hw_init(hwdev);
malidp_se_irq_hw_init(hwdev);
--
2.54.0
next reply other threads:[~2026-05-31 5:30 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-31 5:29 Gustavo Kenji Mendonça Kaneko [this message]
2026-05-31 5:30 ` [PATCH 2/2] drm/arm/komeda: fix ignored clk_prepare_enable() return value in resume Gustavo Kenji Mendonça Kaneko
2026-06-05 12:17 ` Liviu Dudau
2026-06-05 12:07 ` [PATCH 1/2] drm/arm/malidp: fix ignored clk_prepare_enable() in runtime PM resume Liviu Dudau
2026-06-05 14:20 ` Liviu Dudau
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=20260531052945.65117-1-kaneko.dev@pm.me \
--to=kaneko.dev@pm.me \
--cc=airlied@gmail.com \
--cc=dri-devel@lists.freedesktop.org \
--cc=linux-kernel@vger.kernel.org \
--cc=liviu.dudau@arm.com \
--cc=simona@ffwll.ch \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®