Messages in this thread | | | Date | Mon, 4 Jul 2022 08:35:57 -0700 | Subject | Re: [PATCH v2] serial: 8250_bcm7271: Save/restore RTS in suspend/resume | From | Florian Fainelli <> |
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On 7/3/2022 11:40 PM, Jiri Slaby wrote: > On 29. 06. 22, 18:02, Florian Fainelli wrote: >> From: Doug Berger <opendmb@gmail.com> >> >> Commit 9cabe26e65a8 ("serial: 8250_bcm7271: UART errors after resuming >> from S2") prevented an early enabling of RTS during resume, but it did >> not actively restore the RTS state after resume. >> >> Fixes: 9cabe26e65a8 ("serial: 8250_bcm7271: UART errors after resuming >> from S2") >> Signed-off-by: Doug Berger <opendmb@gmail.com> >> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> >> --- >> drivers/tty/serial/8250/8250_bcm7271.c | 24 ++++++++++++++++++------ >> 1 file changed, 18 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/tty/serial/8250/8250_bcm7271.c >> b/drivers/tty/serial/8250/8250_bcm7271.c >> index 9b878d023dac..b9cea38c8aff 100644 >> --- a/drivers/tty/serial/8250/8250_bcm7271.c >> +++ b/drivers/tty/serial/8250/8250_bcm7271.c > ... >> @@ -1180,7 +1184,15 @@ static int __maybe_unused >> brcmuart_resume(struct device *dev) >> start_rx_dma(serial8250_get_port(priv->line)); >> } >> serial8250_resume_port(priv->line); >> - port->mctrl = priv->saved_mctrl; >> + >> + if (priv->saved_mctrl & TIOCM_RTS) { >> + /* Restore RTS */ >> + spin_lock_irqsave(&port->lock, flags); >> + port->mctrl |= TIOCM_RTS; >> + spin_unlock_irqrestore(&port->lock, flags); >> + port->ops->set_mctrl(port, port->mctrl); > > Calling ->set_mctrl w/o port->lock doesn't look really safe.
Good point, I will check with Doug whether this was intentional and if so, why, and if not why should we move it up under the spinlock.
Thanks! -- Florian
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