On Wed, May 11, 2022 at 02:35:05PM +0000, Andrew Cooper wrote: > On 11/05/2022 15:15, Roger Pau Monné wrote: > > On Wed, May 11, 2022 at 03:59:28PM +0200, Marek Marczykowski-Górecki wrote: > >> Intel LPSS has INTERRUPT_LINE set to 0xff by default, that is declared > >> by the PCI Local Bus Specification Revision 3.0 (from 2004) as > >> "unknown"/"no connection". Fallback to poll mode in this case. > >> The 0xff handling is x86-specific, the surrounding code is guarded with > >> CONFIG_X86 anyway. > >> > >> Signed-off-by: Marek Marczykowski-Górecki <[email protected]> > >> --- > >> Changes in v4: > >> - adjust log message, change it from WARNING to INFO > >> - re-add x86 reference in the commit message > >> Changes in v3: > >> - change back to checking 0xff explicitly > >> - adjust commit message, include spec reference > >> - change warning to match the above > >> Changes in v2: > >> - add log message > >> - extend commit message > >> - code style fix > >> --- > >> xen/drivers/char/ns16550.c | 7 +++++++ > >> 1 file changed, 7 insertions(+) > >> > >> diff --git a/xen/drivers/char/ns16550.c b/xen/drivers/char/ns16550.c > >> index fb75cee4a13a..c0d65cff62fe 100644 > >> --- a/xen/drivers/char/ns16550.c > >> +++ b/xen/drivers/char/ns16550.c > >> @@ -1238,6 +1238,13 @@ pci_uart_config(struct ns16550 *uart, bool_t > >> skip_amt, unsigned int idx) > >> pci_conf_read8(PCI_SBDF(0, b, d, f), > >> PCI_INTERRUPT_LINE) : 0; > >> > >> + if ( uart->irq == 0xff ) > >> + uart->irq = 0; > >> + if ( !uart->irq ) > >> + printk(XENLOG_INFO > >> + "ns16550: %pp no legacy IRQ %d, using poll > >> mode\n", > >> + &PCI_SBDF(0, b, d, f), uart->irq); > > There's no point in printing ->irq as it will be 0 or else the message > > won't be printed. > > > > With that fixed: > > > > Reviewed-by: Roger Pau Monné <[email protected]> > > TBH, can be fixed on commit, save another round of patching.
Indeed, thanks for taking care of that. Roger.
