Re: [Regression] CH341 USB-serial converter passes data in 32 byte chunks

Johan Hovold
2022-07-18T14:16:26Z

On Mon, Jul 18, 2022 at 10:53:06AM +0200, Johan Hovold wrote:

> From 82faf260d13c9f01e4af664f31231e5d88d7e4f1 Mon Sep 17 00:00:00 2001
> From: Johan Hovold <johan@kernel.org>
> Date: Mon, 18 Jul 2022 10:21:41 +0200
> Subject: [PATCH] USB: serial: ch341: fix disabled tx timer on older devices
>
> At least one older CH341 appears to have the TX timer enable bit
> inverted so that setting it disables the TX timer and prevents the FIFO
> from emptying until it is full.
>
> Only set the TX timer enable bit for devices with version newer than
> 0x27.
>
> Also try restoring an older init command before updating the line
> settings to see if it has any effect on a lost first byte after
> initialisation.
>
> Reported-by: Jonathan Woithe <jwoithe@just42.net>
> Link: https://lore.kernel.org/r/Ys1iPTfiZRWj2gXs@marvin.atrad.com.au
> Not-Signed-off-yet-by: Johan Hovold <johan@kernel.org>

s/TX/RX/ ...

Johan