On 8/31/23 15:25, Andy Shevchenko wrote:
In case the leaf driver wants to use IRQ polling (irq = 0) and
IIR register shows that an interrupt happened in the 8250 hardware
the IRQ data can be NULL. In such a case we need to skip the wake
event as we came to this path from the timer interrupt and quite
likely system is already awake.
I suppose that is fair to say.
Without this fix we have got an Oops:
serial8250: ttyS0 at I/O 0x3f8 (irq = 0, base_baud = 115200) is a 16550A
...
BUG: kernel NULL pointer dereference, address: 0000000000000010
RIP: 0010:serial8250_handle_irq+0x7c/0x240
Call Trace:
? serial8250_handle_irq+0x7c/0x240
? __pfx_serial8250_timeout+0x10/0x10
Fixes: 0ba9e3a13c6a ("serial: 8250: Add missing wakeup event reporting")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Reviewed-by: Florian Fainelli <florian.fainelli@xxxxxxxxxxxx>
Thanks Andy!
--
Florian
