diff mbox series

[1/2] mwifiex: do no submit URB in suspended state

Message ID 1534837982-31206-1-git-send-email-gbhat@marvell.com (mailing list archive)
State Accepted
Commit 7bd4628c2f31c51254aa39628ecae521d00d0b90
Delegated to: Kalle Valo
Headers show
Series [1/2] mwifiex: do no submit URB in suspended state | expand

Commit Message

Ganapathi Bhat Aug. 21, 2018, 7:53 a.m. UTC 
There is a possible race between USB suspend and main thread:

1. After processing the command response, main thread will submit
rx_cmd URB back so as to process next command response, by
calling mwifiex_usb_submit_rx_urb.

2. During USB suspend, the suspend handler will check if rx_cmd
URB is pending(submitted) and if true, kill this URB.

There is a possible race between #1 and #2, where rx_cmd URB will
be submitted by main thread(#1) after the suspend handler check
in #2.

To fix this, check if device is already suspended in
mwifiex_usb_submit_rx_urb, in which case do not submit the URB.

Signed-off-by: Vidya Dharmaraju <vidyad@marvell.com>
Signed-off-by: Cathy Luo <cluo@marvell.com>
Signed-off-by: Ganapathi Bhat <gbhat@marvell.com>
---
 drivers/net/wireless/marvell/mwifiex/usb.c | 7 +++++++
 1 file changed, 7 insertions(+)

Comments

Kalle Valo Aug. 31, 2018, 3:47 p.m. UTC | #1 
Ganapathi Bhat <gbhat@marvell.com> wrote:

> There is a possible race between USB suspend and main thread:
> 
> 1. After processing the command response, main thread will submit
> rx_cmd URB back so as to process next command response, by
> calling mwifiex_usb_submit_rx_urb.
> 
> 2. During USB suspend, the suspend handler will check if rx_cmd
> URB is pending(submitted) and if true, kill this URB.
> 
> There is a possible race between #1 and #2, where rx_cmd URB will
> be submitted by main thread(#1) after the suspend handler check
> in #2.
> 
> To fix this, check if device is already suspended in
> mwifiex_usb_submit_rx_urb, in which case do not submit the URB.
> 
> Signed-off-by: Vidya Dharmaraju <vidyad@marvell.com>
> Signed-off-by: Cathy Luo <cluo@marvell.com>
> Signed-off-by: Ganapathi Bhat <gbhat@marvell.com>

2 patches applied to wireless-drivers-next.git, thanks.

7bd4628c2f31 mwifiex: do no submit URB in suspended state
33a164fa8a4c mwifex: free rx_cmd skb in suspended state
diff mbox series

Patch

diff --git a/drivers/net/wireless/marvell/mwifiex/usb.c b/drivers/net/wireless/marvell/mwifiex/usb.c
index 433c6a16..76d80fd 100644
--- a/drivers/net/wireless/marvell/mwifiex/usb.c
+++ b/drivers/net/wireless/marvell/mwifiex/usb.c
@@ -298,6 +298,13 @@  static int mwifiex_usb_submit_rx_urb(struct urb_context *ctx, int size)
 	struct mwifiex_adapter *adapter = ctx->adapter;
 	struct usb_card_rec *card = (struct usb_card_rec *)adapter->card;
 
+	if (test_bit(MWIFIEX_IS_SUSPENDED, &adapter->work_flags)) {
+		mwifiex_dbg(adapter, ERROR,
+			    "%s: card removed/suspended, EP %d rx_cmd URB submit skipped\n",
+			    __func__, ctx->ep);
+		return -1;
+	}
+
 	if (card->rx_cmd_ep != ctx->ep) {
 		ctx->skb = dev_alloc_skb(size);
 		if (!ctx->skb) {