Hi, Does cd16044d7c38 ("serial: 8250: dw: enable using pdata with ACPI") work for you? (Currently in tty-linus branch). -- i. On Tue, 28 Jun 2022, Jeremy Linton wrote: > Similarly to e6a08c6949cb, ACPI machines don't have > a pdata setup, leading to a null pointer dereference > when dw8250_handle_irq runs. > > Fixes: aa63d786cea2 ("serial: 8250: dw: Add support for DMA flow controlling devices") > Signed-off-by: Jeremy Linton <jeremy.linton@xxxxxxx> > --- > drivers/tty/serial/8250/8250_dw.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c > index 53e488beb8c2..06f80090cbb9 100644 > --- a/drivers/tty/serial/8250/8250_dw.c > +++ b/drivers/tty/serial/8250/8250_dw.c > @@ -237,10 +237,13 @@ static int dw8250_handle_irq(struct uart_port *p) > struct dw8250_data *d = to_dw8250_data(p->private_data); > unsigned int iir = p->serial_in(p, UART_IIR); > bool rx_timeout = (iir & 0x3f) == UART_IIR_RX_TIMEOUT; > - unsigned int quirks = d->pdata->quirks; > + unsigned int quirks = 0; > unsigned int status; > unsigned long flags; > > + if (d->pdata) > + quirks = d->pdata->quirks; > + > /* > * There are ways to get Designware-based UARTs into a state where > * they are asserting UART_IIR_RX_TIMEOUT but there is no actual >