From c01d2c58698f710c9e13ba3e2d296328606f74fd Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan@kernel.org>
Date: Sun, 25 Oct 2020 18:45:49 +0100
Subject: [PATCH] USB: serial: keyspan_pda: fix stalled writes
Git-commit: c01d2c58698f710c9e13ba3e2d296328606f74fd
Patch-mainline: v5.11-rc1
References: git-fixes
Make sure to clear the write-busy flag also in case no new data was
submitted due to lack of device buffer space so that writing is
resumed once space again becomes available.
Fixes: 507ca9bc0476 ("[PATCH] USB: add ability for usb-serial drivers to determine if their write urb is currently being used.")
Cc: stable <stable@vger.kernel.org> # 2.6.13
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/usb/serial/keyspan_pda.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/usb/serial/keyspan_pda.c b/drivers/usb/serial/keyspan_pda.c
index 17b60e5a9f1f..d6ebde779e85 100644
--- a/drivers/usb/serial/keyspan_pda.c
+++ b/drivers/usb/serial/keyspan_pda.c
@@ -548,7 +548,7 @@ static int keyspan_pda_write(struct tty_struct *tty,
rc = count;
exit:
- if (rc < 0)
+ if (rc <= 0)
set_bit(0, &port->write_urbs_free);
return rc;
}
--
2.26.2