Hello, Le 24/10/2022 à 08:36, Tony Lindgren a écrit : > There are cases where omap8250_set_mctrl() may get called after the > UART has already autoidled causing an asynchronous external abort. > > This can happen on ttyport_open(): > > mem_serial_in from omap8250_set_mctrl+0x38/0xa0 > omap8250_set_mctrl from uart_update_mctrl+0x4c/0x58 > uart_update_mctrl from uart_dtr_rts+0x60/0xa8 > uart_dtr_rts from tty_port_block_til_ready+0xd0/0x2a8 > tty_port_block_til_ready from uart_open+0x14/0x1c > uart_open from ttyport_open+0x64/0x148 > > And on ttyport_close(): > > omap8250_set_mctrl from uart_update_mctrl+0x3c/0x48 > uart_update_mctrl from uart_dtr_rts+0x54/0x9c > uart_dtr_rts from tty_port_shutdown+0x78/0x9c > tty_port_shutdown from tty_port_close+0x3c/0x74 > tty_port_close from ttyport_close+0x40/0x58 > > It can also happen on disassociate_ctty() calling uart_shutdown() > that ends up calling omap8250_set_mctrl(). > > Let's fix the issue by adding missing PM runtime calls to > omap8250_set_mctrl(). To do this, we need to add __omap8250_set_mctrl() > that can be called from both omap8250_set_mctrl(), and from runtime PM > resume path when restoring the registers. Sorry, I'm late but I confirm that this patch fixes my issue [1]. I checked without this patch applied with the 5.10.153-rt76+ kernel and I can reproduce the issue. Tested-by: Romain Naour <romain.naour@xxxxxxxx> [1] https://marc.info/?l=linux-omap&m=164398186306233&w=2 Best regards, Romain > > Fixes: 61929cf0169d ("tty: serial: Add 8250-core based omap driver") > Depends-on: dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter") > Reported-by: Merlijn Wajer <merlijn@xxxxxxxxxx> > Reported-by: Romain Naour <romain.naour@xxxxxxxx> > Reported-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@xxxxxxxxx> > Tested-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@xxxxxxxxx> > Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx> > --- > drivers/tty/serial/8250/8250_omap.c | 22 ++++++++++++++++++++-- > 1 file changed, 20 insertions(+), 2 deletions(-) > > diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c > --- a/drivers/tty/serial/8250/8250_omap.c > +++ b/drivers/tty/serial/8250/8250_omap.c > @@ -157,7 +157,11 @@ static u32 uart_read(struct uart_8250_port *up, u32 reg) > return readl(up->port.membase + (reg << up->port.regshift)); > } > > -static void omap8250_set_mctrl(struct uart_port *port, unsigned int mctrl) > +/* > + * Called on runtime PM resume path from omap8250_restore_regs(), and > + * omap8250_set_mctrl(). > + */ > +static void __omap8250_set_mctrl(struct uart_port *port, unsigned int mctrl) > { > struct uart_8250_port *up = up_to_u8250p(port); > struct omap8250_priv *priv = up->port.private_data; > @@ -181,6 +185,20 @@ static void omap8250_set_mctrl(struct uart_port *port, unsigned int mctrl) > } > } > > +static void omap8250_set_mctrl(struct uart_port *port, unsigned int mctrl) > +{ > + int err; > + > + err = pm_runtime_resume_and_get(port->dev); > + if (err) > + return; > + > + __omap8250_set_mctrl(port, mctrl); > + > + pm_runtime_mark_last_busy(port->dev); > + pm_runtime_put_autosuspend(port->dev); > +} > + > /* > * Work Around for Errata i202 (2430, 3430, 3630, 4430 and 4460) > * The access to uart register after MDR1 Access > @@ -341,7 +359,7 @@ static void omap8250_restore_regs(struct uart_8250_port *up) > > omap8250_update_mdr1(up, priv); > > - up->port.ops->set_mctrl(&up->port, up->port.mctrl); > + __omap8250_set_mctrl(&up->port, up->port.mctrl); > > if (up->port.rs485.flags & SER_RS485_ENABLED) > serial8250_em485_stop_tx(up);
