* Russell King - ARM Linux | 2011-01-07 20:45:36 [+0000]: >On Fri, Jan 07, 2011 at 11:27:18AM +0000, Russell King - ARM Linux wrote: >> I've not been able to characterize whether it's the TX or RX at fault, >> and until I have the OMAP4 device to which the ftdi_sio driver up and >> running, that's impossible for me to do. > >It appears to be the RX side which is getting wedged. Now that my OMAP4 >platform boots to a prompt, I've been able to test various things. > >If I type 'dmesg' then I see it sometimes stop at a random point in the >output. > >If I then exit minicom, I get: > >ftdi_sio ttyUSB2: ftdi_set_termios FAILED to set databits/stopbits/parity >ftdi_sio ttyUSB2: ftdi_set_termios urb failed to set baudrate >ftdi_sio ttyUSB2: urb failed to clear flow control >ftdi_sio ttyUSB2: error from flowcontrol urb > >before minicom finally exits and I get a prompt back. If I then restart >minicom: > >qh is 0 This is strange. The queue head (endpoint) was closed but there is still a package descriptor active. This shouldn't happen. >ftdi_sio ttyUSB2: ftdi_set_termios FAILED to set databits/stopbits/parity > >but it appears to be working again. > >Next time around, I enabled debugging in ftdi_sio. This is everything >that remains in the kernel message buffer: > > >=== this is where stuff goes awol === > >drivers/usb/serial/ftdi_sio.c: ftdi_tiocmget TIOCMGET >drivers/usb/serial/ftdi_sio.c: ftdi_ioctl cmd 0x5402 >drivers/usb/serial/ftdi_sio.c: ftdi_ioctl arg not supported - it was 0x5402 - check /usr/include/asm/ioctls.h >drivers/usb/serial/ftdi_sio.c: ftdi_set_termios >drivers/usb/serial/ftdi_sio.c: Setting CS8 >ftdi_sio ttyUSB2: ftdi_set_termios FAILED to set databits/stopbits/parity This fails while sending an URB. If we run here into the timeout (instead of sending it to an dead end point) then this could be fixed :) The erratum says that is has been observed with usb-to-serial and usb-to-network adapter that the ATL interrupt stop appearing if clear the done map while another interrupt is generated. The suggested workaround is to listen on SOF interrupts instead of ATL and poll the done bits. Sebastian -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
