[PATCH] mmc: mtk-sd: replace use of system_wq with system_percpu_wq

[PATCH] mmc: mtk-sd: replace use of system_wq with system_percpu_wq

[Marco Crivellari]

Currently if a user enqueues 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 consistency 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")

Replace system_wq with system_percpu_wq, keeping the same old behavior.
The old wq (system_wq) will be kept for a few release cycles.

Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
---
 drivers/mmc/host/mtk-sd.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
index 79074291e9d2..daed659f63f6 100644
--- a/drivers/mmc/host/mtk-sd.c
+++ b/drivers/mmc/host/mtk-sd.c
@@ -1214,7 +1214,7 @@ static void msdc_start_data(struct msdc_host *host, struct mmc_command *cmd,
 	host->data = data;
 	read = data->flags & MMC_DATA_READ;
 
-	mod_delayed_work(system_wq, &host->req_timeout, DAT_TIMEOUT);
+	mod_delayed_work(system_percpu_wq, &host->req_timeout, DAT_TIMEOUT);
 	msdc_dma_setup(host, &host->dma, data);
 	sdr_set_bits(host->base + MSDC_INTEN, data_ints_mask);
 	sdr_set_field(host->base + MSDC_DMA_CTRL, MSDC_DMA_CTRL_START, 1);
@@ -1444,7 +1444,7 @@ static void msdc_start_command(struct msdc_host *host,
 	WARN_ON(host->cmd);
 	host->cmd = cmd;
 
-	mod_delayed_work(system_wq, &host->req_timeout, DAT_TIMEOUT);
+	mod_delayed_work(system_percpu_wq, &host->req_timeout, DAT_TIMEOUT);
 	if (!msdc_cmd_is_ready(host, mrq, cmd))
 		return;
 
-- 
2.51.1

Re: [PATCH] mmc: mtk-sd: replace use of system_wq with system_percpu_wq

[AngeloGioacchino Del Regno]

Il 05/11/25 15:58, Marco Crivellari ha scritto:
> Currently if a user enqueues 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 consistency 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")
> 
> Replace system_wq with system_percpu_wq, keeping the same old behavior.
> The old wq (system_wq) will be kept for a few release cycles.
> 
> Suggested-by: Tejun Heo <tj@kernel.org>
> Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>

Re: [PATCH] mmc: mtk-sd: replace use of system_wq with system_percpu_wq

[Ulf Hansson]

On Wed, 5 Nov 2025 at 15:58, Marco Crivellari <marco.crivellari@suse.com> wrote:
>
> Currently if a user enqueues 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 consistency 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")
>
> Replace system_wq with system_percpu_wq, keeping the same old behavior.
> The old wq (system_wq) will be kept for a few release cycles.
>
> Suggested-by: Tejun Heo <tj@kernel.org>
> Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>

Applied for next, thanks!

Kind regards
Uffe


> ---
>  drivers/mmc/host/mtk-sd.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
> index 79074291e9d2..daed659f63f6 100644
> --- a/drivers/mmc/host/mtk-sd.c
> +++ b/drivers/mmc/host/mtk-sd.c
> @@ -1214,7 +1214,7 @@ static void msdc_start_data(struct msdc_host *host, struct mmc_command *cmd,
>         host->data = data;
>         read = data->flags & MMC_DATA_READ;
>
> -       mod_delayed_work(system_wq, &host->req_timeout, DAT_TIMEOUT);
> +       mod_delayed_work(system_percpu_wq, &host->req_timeout, DAT_TIMEOUT);
>         msdc_dma_setup(host, &host->dma, data);
>         sdr_set_bits(host->base + MSDC_INTEN, data_ints_mask);
>         sdr_set_field(host->base + MSDC_DMA_CTRL, MSDC_DMA_CTRL_START, 1);
> @@ -1444,7 +1444,7 @@ static void msdc_start_command(struct msdc_host *host,
>         WARN_ON(host->cmd);
>         host->cmd = cmd;
>
> -       mod_delayed_work(system_wq, &host->req_timeout, DAT_TIMEOUT);
> +       mod_delayed_work(system_percpu_wq, &host->req_timeout, DAT_TIMEOUT);
>         if (!msdc_cmd_is_ready(host, mrq, cmd))
>                 return;
>
> --
> 2.51.1
>

Re: [PATCH] mmc: mtk-sd: replace use of system_wq with system_percpu_wq

[Marco Crivellari]

On Tue, Nov 11, 2025 at 6:37 PM Ulf Hansson <ulf.hansson@linaro.org> wrote:
> [...]
> Applied for next, thanks!
>

Many thanks!

-- 

Marco Crivellari

L3 Support Engineer, Technology & Product