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From:   Haoran Liu <liuhaoran14@163.com>
To:     mchehab@kernel.org
Cc:     linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
        Haoran Liu <liuhaoran14@163.com>
Subject: [PATCH] [media] usbtv: Add error handling for usb_submit_urb in usbtv_audio_start
Date:   Wed, 29 Nov 2023 19:37:35 -0800
Message-Id: <20231130033735.36013-1-liuhaoran14@163.com>
Precedence: bulk

This patch introduces improved error handling for the usb_submit_urb call
in the usbtv_audio_start function. Prior to this change, the function did
not handle the scenario where usb_submit_urb could fail, potentially
leading to inconsistent state and unreliable audio streaming.

Although the error addressed by this patch may not occur in the current
environment, I still suggest implementing these error handling routines
if the function is not highly time-sensitive. As the environment evolves
or the code gets reused in different contexts, there's a possibility that
these errors might occur. Addressing them now can prevent potential
debugging efforts in the future, which could be quite resource-intensive.

Signed-off-by: Haoran Liu <liuhaoran14@163.com>
---
 drivers/media/usb/usbtv/usbtv-audio.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/media/usb/usbtv/usbtv-audio.c b/drivers/media/usb/usbtv/usbtv-audio.c
index 333bd305a4f9..81d6d54fd12c 100644
--- a/drivers/media/usb/usbtv/usbtv-audio.c
+++ b/drivers/media/usb/usbtv/usbtv-audio.c
@@ -172,6 +172,7 @@ static void usbtv_audio_urb_received(struct urb *urb)
 static int usbtv_audio_start(struct usbtv *chip)
 {
 	unsigned int pipe;
+	int err;
 	static const u16 setup[][2] = {
 		/* These seem to enable the device. */
 		{ USBTV_BASE + 0x0008, 0x0001 },
@@ -216,7 +217,15 @@ static int usbtv_audio_start(struct usbtv *chip)
 	usbtv_set_regs(chip, setup, ARRAY_SIZE(setup));
 
 	usb_clear_halt(chip->udev, pipe);
-	usb_submit_urb(chip->snd_bulk_urb, GFP_ATOMIC);
+	err = usb_submit_urb(chip->snd_bulk_urb, GFP_ATOMIC);
+	if (err) {
+		dev_err(&chip->udev->dev,
+			"usb_submit_urb failed: %d\n", err);
+		kfree(chip->snd_bulk_urb->transfer_buffer);
+		usb_free_urb(chip->snd_bulk_urb);
+		chip->snd_bulk_urb = NULL;
+		return err;
+	}
 
 	return 0;
 
-- 
2.17.1