smscore_getbuffer() calls internally wait_event(), with can sleep.
As smsusb_onresponse() is called on interrupt context, this causes
the following warning:
BUG: sleeping function called from invalid context at drivers/media/common/siano/smscoreapi.c:1653
in_atomic(): 1, irqs_disabled(): 1, pid: 11084, name: systemd-udevd
INFO: lockdep is turned off.
irq event stamp: 0
hardirqs last enabled at (0): [< (null)>] (null)
hardirqs last disabled at (0): [<ffffffff811480f7>] copy_process.part.7+0x10e7/0x56d0
softirqs last enabled at (0): [<ffffffff81148193>] copy_process.part.7+0x1183/0x56d0
softirqs last disabled at (0): [< (null)>] (null)
CPU: 2 PID: 11084 Comm: systemd-udevd Tainted: G B W 4.5.0-rc3+ #47
Hardware name: /NUC5i7RYB, BIOS RYBDWi35.86A.0350.2015.0812.1722 08/12/2015
0000000000000000 ffff8803c6907a80 ffffffff81933901 ffff8802bd916000
ffff8802bd9165c8 ffff8803c6907aa8 ffffffff811c6af5 ffff8802bd916000
ffffffffa0ce9b60 0000000000000675 ffff8803c6907ae8 ffffffff811c6ce5
Call Trace:
<IRQ> [<ffffffff81933901>] dump_stack+0x85/0xc4
[<ffffffff811c6af5>] ___might_sleep+0x245/0x3a0
[<ffffffff811c6ce5>] __might_sleep+0x95/0x1a0
[<ffffffffa0ce020a>] ? list_add_locked+0xca/0x140 [smsmdtv]
[<ffffffffa0ce3b8d>] smscore_getbuffer+0x7d/0x120 [smsmdtv]
[<ffffffff8123819d>] ? trace_hardirqs_off+0xd/0x10
[<ffffffffa0ce3b10>] ? smscore_sendrequest_and_wait.isra.5+0x120/0x120 [smsmdtv]
[<ffffffffa0ce020a>] ? list_add_locked+0xca/0x140 [smsmdtv]
[<ffffffffa0ce13ca>] ? smscore_putbuffer+0x3a/0x40 [smsmdtv]
[<ffffffffa0d107bc>] smsusb_submit_urb+0x2ec/0x4f0 [smsusb]
[<ffffffffa0d10e36>] smsusb_onresponse+0x476/0x720 [smsusb]
Let's add a work queue to handle the bottom half, preventing this
problem.
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxx>
---
drivers/media/usb/siano/smsusb.c | 19 ++++++++++++++++++-
1 file changed, 18 insertions(+), 1 deletion(-)
diff --git a/drivers/media/usb/siano/smsusb.c b/drivers/media/usb/siano/smsusb.c
index 6cb4be6dddbb..8e0c05271a33 100644
--- a/drivers/media/usb/siano/smsusb.c
+++ b/drivers/media/usb/siano/smsusb.c
@@ -52,6 +52,9 @@ struct smsusb_urb_t {
struct smsusb_device_t *dev;
struct urb urb;
+
+ /* For the bottom half */
+ struct work_struct wq;
};
struct smsusb_device_t {
@@ -72,6 +75,18 @@ static int smsusb_submit_urb(struct smsusb_device_t *dev,
struct smsusb_urb_t *surb);
/**
+ * Completing URB's callback handler - bottom half (proccess context)
+ * submits the URB prepared on smsusb_onresponse()
+ */
+static void do_submit_urb(struct work_struct *work)
+{
+ struct smsusb_urb_t *surb = container_of(work, struct smsusb_urb_t, wq);
+ struct smsusb_device_t *dev = surb->dev;
+
+ smsusb_submit_urb(dev, surb);
+}
+
+/**
* Completing URB's callback handler - top half (interrupt context)
* adds completing sms urb to the global surbs list and activtes the worker
* thread the surb
@@ -139,13 +154,15 @@ static void smsusb_onresponse(struct urb *urb)
exit_and_resubmit:
- smsusb_submit_urb(dev, surb);
+ INIT_WORK(&surb->wq, do_submit_urb);
+ schedule_work(&surb->wq);
}
static int smsusb_submit_urb(struct smsusb_device_t *dev,
struct smsusb_urb_t *surb)
{
if (!surb->cb) {
+ /* This function can sleep */
surb->cb = smscore_getbuffer(dev->coredev);
if (!surb->cb) {
pr_err("smscore_getbuffer(...) returned NULL\n");
--
2.5.0
--
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