On Thu, Sep 12, 2024 at 10:37:39AM +0200, Jan Kiszka wrote:
> From: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
>
> There are apparently incomplete clones of the HXD type chip in use.
> Those return -EPIPE on GET_LINE_REQUEST and BREAK_REQUEST. Avoid
> flooding the kernel log with those errors. Detect them during startup
> and then use the line_settings cache instead of GET_LINE_REQUEST. Signal
> missing break support via -ENOTTY.
>
> Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
> ---
>
> Changes in v3:
> - use quirks field instead of new type (suggested by Michal)
> #define PL2303_QUIRK_UART_STATE_IDX0 BIT(0)
> #define PL2303_QUIRK_LEGACY BIT(1)
> #define PL2303_QUIRK_ENDPOINT_HACK BIT(2)
> +#define PL2304_QUIRK_NO_BREAK_GETLINE BIT(3)
I believe you meant to use a "PL2303" prefix here as well.
> +static bool pl2303_is_hxd_clone(struct usb_serial *serial)
> +{
> + struct usb_device *udev = serial->dev;
> + unsigned char *buf;
> + int ret;
> +
> + buf = kmalloc(7, GFP_KERNEL);
> + if (!buf) {
> + dev_err(&serial->interface->dev,
> + "could not check for clone type, not enough memory\n");
And there's no need to log out-of-memory errors (e.g. which would
already have been logged by allocator).
> + return false;
> + }
> +
> + ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
> + GET_LINE_REQUEST, GET_LINE_REQUEST_TYPE,
> + 0, 0, buf, 7, 100);
> +
> + kfree(buf);
> +
> + return ret == -EPIPE;
> +}
I fixed up the above when applying. Looks nice and clean otherwise.
Thanks.
Johan
