diff options
| author | Jan Kiszka <jan.kiszka@siemens.com> | 2024-09-12 10:37:39 +0200 |
|---|---|---|
| committer | Johan Hovold <johan@kernel.org> | 2024-11-06 17:23:33 +0100 |
| commit | 40827729cff16269b5e99fc8e12bf53d848407de (patch) | |
| tree | 478b87a0c8d9aa0499df88c4d595df140c64115c | |
| parent | 59b723cd2adbac2a34fc8e12c74ae26ae45bf230 (diff) | |
USB: serial: pl2303: account for deficits of clones
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@siemens.com>
[ johan: fix macro prefix, drop oom error message ]
Signed-off-by: Johan Hovold <johan@kernel.org>
| -rw-r--r-- | drivers/usb/serial/pl2303.c | 38 |
1 files changed, 37 insertions, 1 deletions
diff --git a/drivers/usb/serial/pl2303.c b/drivers/usb/serial/pl2303.c index ad41363e3cea..010688dd9e49 100644 --- a/drivers/usb/serial/pl2303.c +++ b/drivers/usb/serial/pl2303.c @@ -31,6 +31,7 @@ #define PL2303_QUIRK_UART_STATE_IDX0 BIT(0) #define PL2303_QUIRK_LEGACY BIT(1) #define PL2303_QUIRK_ENDPOINT_HACK BIT(2) +#define PL2303_QUIRK_NO_BREAK_GETLINE BIT(3) static const struct usb_device_id id_table[] = { { USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID), @@ -467,6 +468,25 @@ static int pl2303_detect_type(struct usb_serial *serial) return -ENODEV; } +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) + 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; +} + static int pl2303_startup(struct usb_serial *serial) { struct pl2303_serial_private *spriv; @@ -489,6 +509,9 @@ static int pl2303_startup(struct usb_serial *serial) spriv->quirks = (unsigned long)usb_get_serial_data(serial); spriv->quirks |= spriv->type->quirks; + if (type == TYPE_HXD && pl2303_is_hxd_clone(serial)) + spriv->quirks |= PL2303_QUIRK_NO_BREAK_GETLINE; + usb_set_serial_data(serial, spriv); if (type != TYPE_HXN) { @@ -725,9 +748,18 @@ static void pl2303_encode_baud_rate(struct tty_struct *tty, static int pl2303_get_line_request(struct usb_serial_port *port, unsigned char buf[7]) { - struct usb_device *udev = port->serial->dev; + struct usb_serial *serial = port->serial; + struct pl2303_serial_private *spriv = usb_get_serial_data(serial); + struct usb_device *udev = serial->dev; int ret; + if (spriv->quirks & PL2303_QUIRK_NO_BREAK_GETLINE) { + struct pl2303_private *priv = usb_get_serial_port_data(port); + + memcpy(buf, priv->line_settings, 7); + return 0; + } + ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0), GET_LINE_REQUEST, GET_LINE_REQUEST_TYPE, 0, 0, buf, 7, 100); @@ -1064,9 +1096,13 @@ static int pl2303_carrier_raised(struct usb_serial_port *port) static int pl2303_set_break(struct usb_serial_port *port, bool enable) { struct usb_serial *serial = port->serial; + struct pl2303_serial_private *spriv = usb_get_serial_data(serial); u16 state; int result; + if (spriv->quirks & PL2303_QUIRK_NO_BREAK_GETLINE) + return -ENOTTY; + if (enable) state = BREAK_ON; else |