linux-kernel - [PATCH] drm/tilcdc: replace use of system_wq with system_percpu

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Message-ID: <20251104165731.315074-1-marco.crivellari@suse.com>
Date: Tue,  4 Nov 2025 17:57:31 +0100
From: Marco Crivellari <marco.crivellari@...e.com>
To: linux-kernel@...r.kernel.org,
	dri-devel@...ts.freedesktop.org
Cc: Tejun Heo <tj@...nel.org>,
	Lai Jiangshan <jiangshanlai@...il.com>,
	Frederic Weisbecker <frederic@...nel.org>,
	Sebastian Andrzej Siewior <bigeasy@...utronix.de>,
	Marco Crivellari <marco.crivellari@...e.com>,
	Michal Hocko <mhocko@...e.com>,
	Jyri Sarha <jyri.sarha@....fi>,
	Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
	Tomi Valkeinen <tomi.valkeinen@...asonboard.com>,
	Maxime Ripard <mripard@...nel.org>,
	Thomas Zimmermann <tzimmermann@...e.de>,
	David Airlie <airlied@...il.com>,
	Simona Vetter <simona@...ll.ch>
Subject: [PATCH] drm/tilcdc: replace use of system_wq with system_percpu_wq

Currently if a user enqueue a work item using schedule_delayed_work() the
used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use
WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to
schedule_work() that is using system_wq and queue_work(), that makes use
again of WORK_CPU_UNBOUND.

This lack of consistentcy cannot be addressed without refactoring the API.

This patch continues the effort to refactor worqueue APIs, which has begun
with the change introducing new workqueues and a new alloc_workqueue flag:

commit 128ea9f6ccfb ("workqueue: Add system_percpu_wq and system_dfl_wq")
commit 930c2ea566af ("workqueue: Add new WQ_PERCPU flag")

system_wq should be the per-cpu workqueue, yet in this name nothing makes
that clear, so replace system_wq with system_percpu_wq.

The old wq (system_wq) will be kept for a few release cycles.

Suggested-by: Tejun Heo <tj@...nel.org>
Signed-off-by: Marco Crivellari <marco.crivellari@...e.com>
---
 drivers/gpu/drm/tilcdc/tilcdc_crtc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
index b5f60b2b2d0e..57518a4ab4e1 100644
--- a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
+++ b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
@@ -985,7 +985,7 @@ irqreturn_t tilcdc_crtc_irq(struct drm_crtc *crtc)
 				dev_err(dev->dev,
 					"%s(0x%08x): Sync lost flood detected, recovering",
 					__func__, stat);
-				queue_work(system_wq,
+				queue_work(system_percpu_wq,
 					   &tilcdc_crtc->recover_work);
 				tilcdc_write(dev, LCDC_INT_ENABLE_CLR_REG,
 					     LCDC_SYNC_LOST);
-- 
2.51.1