| Message ID | 20180307210825.50709-2-agraf@suse.de |
|---|---|
| State | Accepted |
| Commit | 293b9814d760aa736fb4dc6cf0a579aa431282f6 |
| Headers | show |
| Series | RPi: Drain RX queue on setbrg | expand |
On Wed, Mar 7, 2018 at 9:08 PM, Alexander Graf <agraf@suse.de> wrote: > After the UART was initialized, we may still have bogus data in the > RX queue if it was enabled with incorrect pin muxing before. > > So let's flush the RX queue whenever we initialize baud rates. > > This fixes a regression with the dynamic pinmuxing code when enable_uart=1 > is not set in config.txt. > > Fixes: caf2233b28 ("bcm283x: Add pinctrl driver") > Reported-by: Göran Lundberg <goran@lundberg.email> > Reported-by: Peter Robinson <pbrobinson@gmail.com> > Signed-off-by: Alexander Graf <agraf@suse.de> Tested-by: Peter Robinson <pbrobinson@gmail.com> > --- > drivers/serial/serial_bcm283x_mu.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/drivers/serial/serial_bcm283x_mu.c b/drivers/serial/serial_bcm283x_mu.c > index 40029fadbc..d87b44e902 100644 > --- a/drivers/serial/serial_bcm283x_mu.c > +++ b/drivers/serial/serial_bcm283x_mu.c > @@ -51,6 +51,8 @@ struct bcm283x_mu_priv { > struct bcm283x_mu_regs *regs; > }; > > +static int bcm283x_mu_serial_getc(struct udevice *dev); > + > static int bcm283x_mu_serial_setbrg(struct udevice *dev, int baudrate) > { > struct bcm283x_mu_serial_platdata *plat = dev_get_platdata(dev); > @@ -59,13 +61,17 @@ static int bcm283x_mu_serial_setbrg(struct udevice *dev, int baudrate) > u32 divider; > > if (plat->skip_init) > - return 0; > + goto out; > > divider = plat->clock / (baudrate * 8); > > writel(BCM283X_MU_LCR_DATA_SIZE_8, ®s->lcr); > writel(divider - 1, ®s->baud); > > +out: > + /* Flush the RX queue - all data in there is bogus */ > + while (bcm283x_mu_serial_getc(dev) != -EAGAIN) ; > + > return 0; > } > > -- > 2.12.3 >
On Wed, 7 Mar 2018 22:08:24 +0100 Alexander Graf <agraf@suse.de> wrote: > After the UART was initialized, we may still have bogus data in the > RX queue if it was enabled with incorrect pin muxing before. > > So let's flush the RX queue whenever we initialize baud rates. > > This fixes a regression with the dynamic pinmuxing code when enable_uart=1 > is not set in config.txt. > > Fixes: caf2233b28 ("bcm283x: Add pinctrl driver") > Reported-by: Göran Lundberg <goran@lundberg.email> > Reported-by: Peter Robinson <pbrobinson@gmail.com> > Signed-off-by: Alexander Graf <agraf@suse.de> > --- > drivers/serial/serial_bcm283x_mu.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > On a RPi 1, with no enable_uart in config.txt: Tested-by: Tuomas Tynkkynen <tuomas@tuxera.com>
On Wed, Mar 07, 2018 at 10:08:24PM +0100, Alexander Graf wrote: > After the UART was initialized, we may still have bogus data in the > RX queue if it was enabled with incorrect pin muxing before. > > So let's flush the RX queue whenever we initialize baud rates. > > This fixes a regression with the dynamic pinmuxing code when enable_uart=1 > is not set in config.txt. > > Fixes: caf2233b28 ("bcm283x: Add pinctrl driver") > Reported-by: Göran Lundberg <goran@lundberg.email> > Reported-by: Peter Robinson <pbrobinson@gmail.com> > Signed-off-by: Alexander Graf <agraf@suse.de> > Tested-by: Peter Robinson <pbrobinson@gmail.com> > Tested-by: Tuomas Tynkkynen <tuomas@tuxera.com> Applied to u-boot/master, thanks! -- Tom
diff --git a/drivers/serial/serial_bcm283x_mu.c b/drivers/serial/serial_bcm283x_mu.c index 40029fadbc..d87b44e902 100644 --- a/drivers/serial/serial_bcm283x_mu.c +++ b/drivers/serial/serial_bcm283x_mu.c @@ -51,6 +51,8 @@ struct bcm283x_mu_priv { struct bcm283x_mu_regs *regs; }; +static int bcm283x_mu_serial_getc(struct udevice *dev); + static int bcm283x_mu_serial_setbrg(struct udevice *dev, int baudrate) { struct bcm283x_mu_serial_platdata *plat = dev_get_platdata(dev); @@ -59,13 +61,17 @@ static int bcm283x_mu_serial_setbrg(struct udevice *dev, int baudrate) u32 divider; if (plat->skip_init) - return 0; + goto out; divider = plat->clock / (baudrate * 8); writel(BCM283X_MU_LCR_DATA_SIZE_8, ®s->lcr); writel(divider - 1, ®s->baud); +out: + /* Flush the RX queue - all data in there is bogus */ + while (bcm283x_mu_serial_getc(dev) != -EAGAIN) ; + return 0; }
After the UART was initialized, we may still have bogus data in the RX queue if it was enabled with incorrect pin muxing before. So let's flush the RX queue whenever we initialize baud rates. This fixes a regression with the dynamic pinmuxing code when enable_uart=1 is not set in config.txt. Fixes: caf2233b28 ("bcm283x: Add pinctrl driver") Reported-by: Göran Lundberg <goran@lundberg.email> Reported-by: Peter Robinson <pbrobinson@gmail.com> Signed-off-by: Alexander Graf <agraf@suse.de> --- drivers/serial/serial_bcm283x_mu.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)