[PATCH 8/8] char: xillybus: Cancel delayed work items before teardown

[Eli Billauer <eli.billauer@gmail.com>]

xillybus_core queues only delayed work items in its workqueue. Use
cancel_delayed_work_sync() instead of flush_workqueue() to clean up
queued work items, as the latter does not wait for or cancel delayed
work items whose timers have not yet expired.

Assisted-by: Sashiko-0.2.5:gemini-3.1-pro-preview
Link: https://sashiko.dev/#/patchset/20260630092330.43534-1-eli.billauer@gmail.com
Signed-off-by: Eli Billauer <eli.billauer@gmail.com>
---
 drivers/char/xillybus/xillybus_core.c | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/drivers/char/xillybus/xillybus_core.c b/drivers/char/xillybus/xillybus_core.c
index ab8ac78b28dc..644447502d09 100644
--- a/drivers/char/xillybus/xillybus_core.c
+++ b/drivers/char/xillybus/xillybus_core.c
@@ -1926,9 +1926,10 @@ struct xilly_endpoint *xillybus_init_endpoint(struct device *dev)
 }
 EXPORT_SYMBOL(xillybus_init_endpoint);
 
-static int xilly_quiesce(struct xilly_endpoint *endpoint)
+static int xilly_quiesce(struct xilly_endpoint *endpoint, int to_cancel)
 {
 	long t;
+	int i;
 
 	endpoint->idtlen = -1;
 	endpoint->num_channels = 0;
@@ -1944,6 +1945,9 @@ static int xilly_quiesce(struct xilly_endpoint *endpoint)
 
 	xilly_allow_isr(endpoint, false);
 
+	for (i = 1; i <= to_cancel; i++)
+		cancel_delayed_work_sync(&endpoint->channels[i]->rd_workitem);
+
 	if (t <= 0) {
 		dev_err(endpoint->dev,
 			"Failed to quiesce the device on exit.\n");
@@ -1956,6 +1960,7 @@ int xillybus_endpoint_discovery(struct xilly_endpoint *endpoint)
 {
 	int rc;
 	long t;
+	int quiesce_channels = 0;
 
 	void *bootstrap_resources;
 	int idtbuffersize = (1 << PAGE_SHIFT);
@@ -2058,6 +2063,7 @@ int xillybus_endpoint_discovery(struct xilly_endpoint *endpoint)
 		goto failed_idt;
 
 	xilly_allow_isr(endpoint, true);
+	quiesce_channels = endpoint->num_channels;
 
 	rc = xillybus_init_chrdev(dev, &xillybus_fops,
 				  endpoint->owner, endpoint,
@@ -2074,8 +2080,7 @@ int xillybus_endpoint_discovery(struct xilly_endpoint *endpoint)
 	return 0;
 
 failed_idt:
-	xilly_quiesce(endpoint);
-	flush_workqueue(xillybus_wq);
+	xilly_quiesce(endpoint, quiesce_channels);
 
 	return rc;
 }
@@ -2085,13 +2090,7 @@ void xillybus_endpoint_remove(struct xilly_endpoint *endpoint)
 {
 	xillybus_cleanup_chrdev(endpoint, endpoint->dev);
 
-	xilly_quiesce(endpoint);
-
-	/*
-	 * Flushing is done upon endpoint release to prevent access to memory
-	 * just about to be released. This makes the quiesce complete.
-	 */
-	flush_workqueue(xillybus_wq);
+	xilly_quiesce(endpoint, endpoint->num_channels);
 }
 EXPORT_SYMBOL(xillybus_endpoint_remove);
 
@@ -2106,7 +2105,7 @@ static int __init xillybus_init(void)
 
 static void __exit xillybus_exit(void)
 {
-	/* flush_workqueue() was called for each endpoint released */
+	/* Work items have been canceled for each endpoint separately */
 	destroy_workqueue(xillybus_wq);
 }
 
-- 
2.17.1