kernel/drivers/usb/serial/ch341.c, branch linux-6.5.y

USB: serial: return errors from break handling

2023-06-07T15:00:23Z

Start propagating errors to user space when setting the break state fails. This will be used by follow-on changes to also report when a driver or device does not support break control. Tested-by: Corey Minyard Signed-off-by: Johan Hovold

Merge 6.0-rc4 into tty-next

2022-09-05T05:59:28Z

We need the tty/serial fixes in here as well. Signed-off-by: Greg Kroah-Hartman

USB: serial: ch341: fix disabled rx timer on older devices

2022-08-31T13:51:06Z

At least one older CH341 appears to have the RX timer enable bit inverted so that setting it disables the RX timer and prevents the FIFO from emptying until it is full. Only set the RX timer enable bit for devices with version newer than 0x27 (even though this probably affects all pre-0x30 devices). Reported-by: Jonathan Woithe Tested-by: Jonathan Woithe Link: https://lore.kernel.org/r/Ys1iPTfiZRWj2gXs@marvin.atrad.com.au Fixes: 4e46c410e050 ("USB: serial: ch341: reinitialize chip on reconfiguration") Cc: stable@vger.kernel.org # 4.10 Signed-off-by: Johan Hovold

USB: serial: ch341: fix lost character on LCR updates

2022-08-31T13:50:53Z

Disable LCR updates for pre-0x30 devices which use a different (unknown) protocol for line control and where the current register write causes the next received character to be lost. Note that updating LCR using the INIT command has no effect on these devices either. Reported-by: Jonathan Woithe Tested-by: Jonathan Woithe Link: https://lore.kernel.org/r/Ys1iPTfiZRWj2gXs@marvin.atrad.com.au Fixes: 4e46c410e050 ("USB: serial: ch341: reinitialize chip on reconfiguration") Fixes: 55fa15b5987d ("USB: serial: ch341: fix baud rate and line-control handling") Cc: stable@vger.kernel.org # 4.10 Signed-off-by: Johan Hovold

usb: serial: Make ->set_termios() old ktermios const

2022-08-30T12:22:35Z

There should be no reason to adjust old ktermios which is going to get discarded anyway. Reviewed-by: Andy Shevchenko Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20220816115739.10928-8-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

Revert "USB: serial: ch341: add new Product ID for CH341A"

2022-02-21T08:58:14Z

This reverts commit 46ee4abb10a07bd8f8ce910ee6b4ae6a947d7f63. CH341 has Product ID 0x5512 in EPP/MEM mode which is used for I2C/SPI/GPIO interfaces. In asynchronous serial interface mode CH341 has PID 0x5523 which is already in the table. Mode is selected by corresponding jumper setting. Signed-off-by: Dmytro Bagrii Link: https://lore.kernel.org/r/20220210164137.4376-1-dimich.dmb@gmail.com Link: https://lore.kernel.org/r/YJ0OCS/sh+1ifD/q@hovoldconsulting.com Cc: stable@vger.kernel.org Signed-off-by: Johan Hovold

USB: serial: ch341: add support for GW Instek USB2.0-Serial devices

2022-01-31T10:35:06Z

Programmable lab power supplies made by GW Instek, such as the GPP-2323, have a USB port exposing a serial port to control the device. Stringing the supplied Windows driver, references to the ch341 chip are found. Binding the existing ch341 driver to the VID/PID of the GPP-2323 ("GW Instek USB2.0-Serial" as per the USB product name) works out of the box, communication and control is now possible. This patch should work with any GPP series power supply due to similarities in the product line. Signed-off-by: Stephan Brunner Link: https://lore.kernel.org/r/4a47b864-0816-6f6a-efee-aa20e74bcdc6@stephan-brunner.net Cc: stable@vger.kernel.org Signed-off-by: Johan Hovold

USB: serial: ch314: use usb_control_msg_recv()

2021-10-27T12:34:59Z

usb_control_msg_recv() is a new wrapper function for usb_control_msg() that has error checks for short reads. This function also accepts data buffer on stack. Hence use this function to simplify error handling for short reads. Short reads will now get reported as -EREMOTEIO with no indication of how short the transfer was. Signed-off-by: Himadri Pandya Link: https://lore.kernel.org/r/20211001065720.21330-2-himadrispandya@gmail.com [ johan: fix quirk-detection breakage, style changes ] Signed-off-by: Johan Hovold

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

2021-08-25T07:13:33Z

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 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 Link: https://lore.kernel.org/r/20210824121926.19311-1-johan@kernel.org Signed-off-by: Johan Hovold

USB: serial: ch341: fix character loss at high transfer rates

2021-07-29T11:52:10Z

The chip supports high transfer rates, but with the small default buffers (64 bytes read), some entire blocks are regularly lost. This typically happens at 1.5 Mbps (which is the default speed on Rockchip devices) when used as a console to access U-Boot where the output of the "help" command misses many lines and where "printenv" mangles the environment. The FTDI driver doesn't suffer at all from this. One difference is that it uses 512 bytes rx buffers and 256 bytes tx buffers. Adopting these values completely resolved the issue, even the output of "dmesg" is reliable. I preferred to leave the Tx value unchanged as it is not involved in this issue, while a change could increase the risk of triggering the same issue with other devices having too small buffers. I verified that it backports well (and works) at least to 5.4. It's of low importance enough to be dropped where it doesn't trivially apply anymore. Cc: stable@vger.kernel.org Signed-off-by: Willy Tarreau Link: https://lore.kernel.org/r/20210724152739.18726-1-w@1wt.eu Signed-off-by: Johan Hovold