From: Johan Hovold <johan@kernel.org> stable inclusion from linux-4.19.206 commit 56c653382239adab6a1b7d4a23ad2e3d5fe2885b -------------------------------- commit df7b16d1c00ecb3da3a30c999cdb39f273c99a2f upstream. This reverts commit 3c18e9baee0ef97510dcda78c82285f52626764b. These devices do not appear to send a zero-length packet when the transfer size is a multiple of the bulk-endpoint max-packet size. This means that incoming data may not be processed by the driver until a short packet is received or the receive buffer is full. Revert back to using endpoint-sized receive buffers to avoid stalled reads. Reported-by: Paul Größel <pb.g@gmx.de> Link: https://bugzilla.kernel.org/show_bug.cgi?id=214131 Fixes: 3c18e9baee0e ("USB: serial: ch341: fix character loss at high transfer rates") Cc: stable@vger.kernel.org Cc: Willy Tarreau <w@1wt.eu> Link: https://lore.kernel.org/r/20210824121926.19311-1-johan@kernel.org Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- drivers/usb/serial/ch341.c | 1 - 1 file changed, 1 deletion(-) diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c index e6dce35ca1aa9..c87cb25e70ec5 100644 --- a/drivers/usb/serial/ch341.c +++ b/drivers/usb/serial/ch341.c @@ -625,7 +625,6 @@ static struct usb_serial_driver ch341_device = { .owner = THIS_MODULE, .name = "ch341-uart", }, - .bulk_in_size = 512, .id_table = id_table, .num_ports = 1, .open = ch341_open, -- 2.25.1