| Message ID | 201408031601.53597.cat.schulze@alice-dsl.net |
|---|---|
| State | Accepted |
| Delegated to: | David Miller |
| Headers | show |
From: Christopher Alexander Tobias Schulze <cat.schulze@alice-dsl.net> Date: Sun, 3 Aug 2014 16:01:53 +0200 > From: Christopher Alexander Tobias Schulze <cat.schulze@alice-dsl.net> > > Fix detection of BREAK on sunsab serial console: BREAK detection was only > performed when there were also serial characters received simultaneously. > To handle all BREAKs correctly, the check for BREAK and the corresponding > call to uart_handle_break() must also be done if count == 0, therefore > duplicate this code fragment and pull it out of the loop over the received > characters. > > Signed-off-by: Christopher Alexander Tobias Schulze <cat.schulze@alice-dsl.net> Applied and queued up for -stable, thanks. But this function needs more work. For one thing, it needs to resample the status registers to update the stat->foo values each loop iteration, otherwise it will report break, overflow, etc. over and over again until we get the next interrupt. Serial chips seem to handle bare-break characters differently. The 8250 seems to indicate "data ready" in it's status register in such cases (and I suppose provides a zero character byte), whereas SAB seems to not put any bytes in it's FIFO in this situation. -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff -Naupr linux-3.16-rc6-orig/drivers/tty/serial/sunsab.c linux-3.16-rc6-patched/drivers/tty/serial/sunsab.c --- linux-3.16-rc6-orig/drivers/tty/serial/sunsab.c 2014-07-27 11:50:32.000000000 +0200 +++ linux-3.16-rc6-patched/drivers/tty/serial/sunsab.c 2014-08-03 15:59:41.000000000 +0200 @@ -157,6 +157,15 @@ receive_chars(struct uart_sunsab_port *u (up->port.line == up->port.cons->index)) saw_console_brk = 1; + if (count == 0) { + if (unlikely(stat->sreg.isr1 & SAB82532_ISR1_BRK)) { + stat->sreg.isr0 &= ~(SAB82532_ISR0_PERR | + SAB82532_ISR0_FERR); + up->port.icount.brk++; + uart_handle_break(&up->port); + } + } + for (i = 0; i < count; i++) { unsigned char ch = buf[i], flag;