On 25.04.2023 16:39, Marek Marczykowski-Górecki wrote: > pci_serial_early_init() enables PCI_COMMAND_IO for IO-based UART > devices, add setting PCI_COMMAND_MEMORY for MMIO-based UART devices too.
This sentence is odd, as by its grammar it looks to describe the current situation only. The respective sentence in v1 did not have this issue. > --- a/xen/drivers/char/ns16550.c > +++ b/xen/drivers/char/ns16550.c > @@ -272,7 +272,15 @@ static int cf_check ns16550_getc(struct serial_port > *port, char *pc) > static void pci_serial_early_init(struct ns16550 *uart) > { > #ifdef NS16550_PCI > - if ( !uart->ps_bdf_enable || uart->io_base >= 0x10000 ) > + if ( uart->bar ) > + { > + pci_conf_write16(PCI_SBDF(0, uart->ps_bdf[0], uart->ps_bdf[1], > + uart->ps_bdf[2]), > + PCI_COMMAND, PCI_COMMAND_MEMORY); > + return; > + } > + > + if ( !uart->ps_bdf_enable ) > return; > > if ( uart->pb_bdf_enable ) While I did suggest using uart->bar, my implication was that the io_base check would then remain in place. Otherwise, if I'm not mistaken, MMIO- based devices not specified via "com<N>=...,pci" would then wrongly take the I/O port path. Furthermore - you can't use uart->bar alone here, can you? The field is set equally for MMIO and port based cards in pci_uart_config(). Jan