This is a note to let you know that I've just added the patch titled USB: serial: keyspan_pda: fix stalled writes to my usb git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git in the usb-testing branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will be merged to the usb-next branch sometime soon, after it passes testing, and the merge window is open. If you have any questions about this process, please let me know. >From c01d2c58698f710c9e13ba3e2d296328606f74fd Mon Sep 17 00:00:00 2001 From: Johan Hovold <johan@xxxxxxxxxx> Date: Sun, 25 Oct 2020 18:45:49 +0100 Subject: USB: serial: keyspan_pda: fix stalled writes 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@xxxxxxxxxxxxxxx> # 2.6.13 Acked-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Johan Hovold <johan@xxxxxxxxxx> --- 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; } -- 2.29.2