[PATCH] Revert "USB: serial: ch341: fix character loss at high transfer rates"

From: Johan Hovold
Date: Tue Aug 24 2021 - 08:20:14 EST


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@xxxxxx>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=214131
Fixes: 3c18e9baee0e ("USB: serial: ch341: fix character loss at high transfer rates")
Cc: stable@xxxxxxxxxxxxxxx
Cc: Willy Tarreau <w@xxxxxx>
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
---
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 8a521b5ea769..2db917eab799 100644
--- a/drivers/usb/serial/ch341.c
+++ b/drivers/usb/serial/ch341.c
@@ -851,7 +851,6 @@ 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,
--
2.31.1