[PATCH v2] wfx: avoid flush_workqueue(system_highpri_wq) usage

Tetsuo Handa
2022-05-02T08:16:26Z

Flushing system-wide workqueues is dangerous and will be forbidden.
Replace system_highpri_wq with per "struct wfx_dev" bh_wq.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
---
Note: This patch is only compile tested.

Changes in v2:
Use per "struct wfx_dev" workqueue.

drivers/net/wireless/silabs/wfx/bh.c | 6 +++---
drivers/net/wireless/silabs/wfx/hif_tx.c | 2 +-
drivers/net/wireless/silabs/wfx/main.c | 6 ++++++
drivers/net/wireless/silabs/wfx/wfx.h | 1 +
4 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/silabs/wfx/bh.c b/drivers/net/wireless/silabs/wfx/bh.c
index bcea9d5b119c..21dfdcf9cc27 100644
--- a/drivers/net/wireless/silabs/wfx/bh.c
+++ b/drivers/net/wireless/silabs/wfx/bh.c
@@ -267,7 +267,7 @@ void wfx_bh_request_rx(struct wfx_dev *wdev)
wfx_control_reg_read(wdev, &cur);
prev = atomic_xchg(&wdev->hif.ctrl_reg, cur);
complete(&wdev->hif.ctrl_ready);
- queue_work(system_highpri_wq, &wdev->hif.bh);
+ queue_work(wdev->bh_wq, &wdev->hif.bh);

if (!(cur & CTRL_NEXT_LEN_MASK))
dev_err(wdev->dev, "unexpected control register value: length field is 0: %04x\n",
@@ -280,7 +280,7 @@ void wfx_bh_request_rx(struct wfx_dev *wdev)
/* Driver want to send data */
void wfx_bh_request_tx(struct wfx_dev *wdev)
{
- queue_work(system_highpri_wq, &wdev->hif.bh);
+ queue_work(wdev->bh_wq, &wdev->hif.bh);
}

/* If IRQ is not available, this function allow to manually poll the control register and simulate
@@ -295,7 +295,7 @@ void wfx_bh_poll_irq(struct wfx_dev *wdev)
u32 reg;

WARN(!wdev->poll_irq, "unexpected IRQ polling can mask IRQ");
- flush_workqueue(system_highpri_wq);
+ flush_workqueue(wdev->bh_wq);
start = ktime_get();
for (;;) {
wfx_control_reg_read(wdev, &reg);
diff --git a/drivers/net/wireless/silabs/wfx/hif_tx.c b/drivers/net/wireless/silabs/wfx/hif_tx.c
index 9c653d0e9034..d35dd940d968 100644
--- a/drivers/net/wireless/silabs/wfx/hif_tx.c
+++ b/drivers/net/wireless/silabs/wfx/hif_tx.c
@@ -73,7 +73,7 @@ int wfx_cmd_send(struct wfx_dev *wdev, struct wfx_hif_msg *request,

if (no_reply) {
/* Chip won't reply. Ensure the wq has send the buffer before to continue. */
- flush_workqueue(system_highpri_wq);
+ flush_workqueue(wdev->bh_wq);
ret = 0;
goto end;
}
diff --git a/drivers/net/wireless/silabs/wfx/main.c b/drivers/net/wireless/silabs/wfx/main.c
index e575a81ca2ca..e015bfb8d221 100644
--- a/drivers/net/wireless/silabs/wfx/main.c
+++ b/drivers/net/wireless/silabs/wfx/main.c
@@ -345,6 +345,10 @@ int wfx_probe(struct wfx_dev *wdev)
wdev->pdata.gpio_wakeup = NULL;
wdev->poll_irq = true;

+ wdev->bh_wq = alloc_workqueue("wfx_bh_wq", WQ_HIGHPRI, 0);
+ if (!wdev->bh_wq)
+ return -ENOMEM;
+
wfx_bh_register(wdev);

err = wfx_init_device(wdev);
@@ -458,6 +462,7 @@ int wfx_probe(struct wfx_dev *wdev)
wdev->hwbus_ops->irq_unsubscribe(wdev->hwbus_priv);
bh_unregister:
wfx_bh_unregister(wdev);
+ destroy_workqueue(wdev->bh_wq);
return err;
}

@@ -467,6 +472,7 @@ void wfx_release(struct wfx_dev *wdev)
wfx_hif_shutdown(wdev);
wdev->hwbus_ops->irq_unsubscribe(wdev->hwbus_priv);
wfx_bh_unregister(wdev);
+ destroy_workqueue(wdev->bh_wq);
}

static int __init wfx_core_init(void)
diff --git a/drivers/net/wireless/silabs/wfx/wfx.h b/drivers/net/wireless/silabs/wfx/wfx.h
index 6594cc647c2f..6f5e95dae21f 100644
--- a/drivers/net/wireless/silabs/wfx/wfx.h
+++ b/drivers/net/wireless/silabs/wfx/wfx.h
@@ -57,6 +57,7 @@ struct wfx_dev {
struct mutex rx_stats_lock;
struct wfx_hif_tx_power_loop_info tx_power_loop_info;
struct mutex tx_power_loop_info_lock;
+ struct workqueue_struct *bh_wq;
};

struct wfx_vif {
--
2.34.1