On Wed, Jul 13, 2005 at 11:04:56AM -0600, Alex Williamson wrote: > On Mon, 2005-07-11 at 15:17 -0600, Alex Williamson wrote: > > No, I think this is a problem with the broken A2 UARTs getting > > confused in serial8250_set_sleep(). If I remove either UART_CAP_SLEEP > > or UART_CAP_EFR from the capabilities list for this UART, it behaves > > normally. Also, just commenting out the UART_CAP_EFR chunks of > > set_sleep make it behave. I'll ping Exar for more data. Thanks, > > Hi Russell, > > I don't know enough about the extended UART programming model, but I > notice that when UART_CAP_EFR and UART_CAP_SLEEP are set on a UART, we > set the UART_IERX_SLEEP bit in the UART_IER immediately after it's found > and configured.
Ah, I see what's happening. We're detecting the port and doing the autoconfig. Then we're checking to see if it's the console, and if not putting it into low power mode. Then we try to register the console, which may result in this UART becoming a console. So now we have a console which is in low power mode. Bad bad bad. No cookie for the serial layer today. > Are there known working configs where a UART w/ EFR and SLEEP are > able to be used as a serial console? No idea - I'm completely reliant on other folk to report problems with the 8250 driver with their random versions of UARTs which are out in the field. I only have 16450, 16550A and 16750 UARTs here. Hmm, I need to consider killing register_serial() and the associated code in serial_core.c earlier so I can sanely fix this problem. I think it's time to give the remaining register_serial() users an extra push... I haven't seen _any_ activity from the remaining users, so I might have to take the attitude that "if they don't care, I don't care about breaking their code" which would be rather shameful as far as the users go. (but hey, user pressure might wake up the maintainers.) -- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: 2.6 Serial core - 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/
