On Mon, Oct 19, 2015 at 4:14 AM, Oliver Neukum <[email protected]> wrote: > On Thu, 2015-10-15 at 17:06 -0500, Konstantin Shkolnyy wrote: >> cp2108 GET_LINE_CTL returns the 16-bit value with the 2 bytes swapped. >> However, SET_LINE_CTL functions properly. When the driver tries to modify >> the register, it reads it, modifies some bits and writes back. Because the >> read bytes were swapped, this often results in an invalid value to be >> written. >> In turn, this causes cp2108 respond with a stall. The stall sometimes doesn't >> clear properly and cp2108 starts responding to following valid commands also >> with stalls, effectively failing. > > Just a remark. >> >> @@ -865,18 +888,53 @@ static void cp210x_break_ctl(struct tty_struct *tty, >> int break_state) >> >> static int cp210x_startup(struct usb_serial *serial) >> { >> + struct usb_serial_port *port; >> struct usb_host_interface *cur_altsetting; >> struct cp210x_serial_private *spriv; >> + unsigned int line_ctl; >> + int err; >> + >> + /* We always expect a single port only */ >> + if (serial->num_ports != 1) { >> + dev_err(&serial->dev->dev, "%s - expected 1 port, found %d\n", >> + __func__, serial->num_ports); >> + return -EINVAL; >> + } > > Why do you introduce this new check? It has no obvious connect with the > subject of this fix.
Because I later use the port[0] field that this function hasn't touched before. But this all will go away in the new version of the patch. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
