From: Peter Hurley <pe...@hurleysoftware.com> Date: Tue, 05 Mar 2013 15:47:04 -0500
> On Tue, 2013-03-05 at 15:03 -0500, David Miller wrote: >> From: Jiri Slaby <jsl...@suse.cz> >> Date: Tue, 05 Mar 2013 20:44:49 +0100 >> >> > Hi, I must admit I don't understand. I now checked both of them and they >> > call uart_handle_sysrq_char unconditionally, or? >> >> Nope, in the sunsab.c receive function, we used to handle the SYSRQ >> stuff before break checking when TTY is NULL, now we don't. > > Hi David, > > SysRq is signalled first by a BRK condition, then followed by the input > character indicating which SysRq function to perform. > > sunsab.c: receive_char() is behaving as you would expect. > > First, a BRK status is indicated so uart_handle_break() records a > timestamp. If the next input is received within 5 sec. of that > timestamp, the character received is interpreted as a SysRq function -- > handled by uart_handle_sysrq_char(). > > Are you observing that SysRq processing is not occurring with this > driver when only a console exists, or are you hypothesizing that this is > possible? Before we go down this road we need to first address the fact that non-trivial semantic changes we made to these functions without any of that being documented. And it was done to a large swath of serial and TTY drivers. The author of these changes doesn't even grok that receive interrupts for these devices can be enabled even if TTY is NULL. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
