Subject: [PATCH AUTOSEL 4.19 065/205] mwifiex: do no submit URB in suspended state

From: Sasha Levin <[email-masked]>
Date: Fri, 8 Nov 2019 06:35:32 -0500

From: Ganapathi Bhat <[email-masked]>

[ Upstream commit 7bd4628c2f31c51254aa39628ecae521d00d0b90 ]

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 <[email-masked]>
Signed-off-by: Cathy Luo <[email-masked]>
Signed-off-by: Ganapathi Bhat <[email-masked]>
Signed-off-by: Kalle Valo <[email-masked]>
Signed-off-by: Sasha Levin <[email-masked]>
---
 drivers/net/wireless/marvell/mwifiex/usb.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/net/wireless/marvell/mwifiex/usb.c b/drivers/net/wireless/marvell/mwifiex/usb.c
index 433c6a16870b6..76d80fd545236 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) {
-- 
2.20.1