| Message ID | 20230110192407.1874044-2-loic.poulain@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v3,1/2] serial: mxc: Wait for TX completion before reset | expand |
On Tue, Jan 10, 2023 at 4:24 PM Loic Poulain <loic.poulain@linaro.org> wrote: > > Instead of waiting for empty FIFO condition before writing a > character, wait for non-full FIFO condition. > > This helps in saving several tens of milliseconds during boot > (depending verbosity). > > Signed-off-by: Loic Poulain <loic.poulain@linaro.org> > Tested-by: Lothar Waßmann <LW@KARO-electronics.de> > --- > v2: fixing transfert abort & char corruption commit > v3: Reordering commits for good bisectability Reviewed-by: Fabio Estevam <festevam@denx.de> Thanks
On Tuesday 10 January 2023 20:24:07 Loic Poulain wrote: > Instead of waiting for empty FIFO condition before writing a > character, wait for non-full FIFO condition. > > This helps in saving several tens of milliseconds during boot > (depending verbosity). > > Signed-off-by: Loic Poulain <loic.poulain@linaro.org> > Tested-by: Lothar Waßmann <LW@KARO-electronics.de> > --- > v2: fixing transfert abort & char corruption commit > v3: Reordering commits for good bisectability > > drivers/serial/serial_mxc.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/drivers/serial/serial_mxc.c b/drivers/serial/serial_mxc.c > index 3c89781f2c..9899155c00 100644 > --- a/drivers/serial/serial_mxc.c > +++ b/drivers/serial/serial_mxc.c > @@ -238,11 +238,11 @@ static void mxc_serial_putc(const char c) > if (c == '\n') > serial_putc('\r'); > > - writel(c, &mxc_base->txd); > - > /* wait for transmitter to be ready */ > - while (!(readl(&mxc_base->ts) & UTS_TXEMPTY)) > + while (readl(&mxc_base->ts) & UTS_TXFULL) > schedule(); > + > + writel(c, &mxc_base->txd); > } > > /* Test whether a character is in the RX buffer */ > @@ -333,7 +333,7 @@ static int mxc_serial_putc(struct udevice *dev, const char ch) > struct mxc_serial_plat *plat = dev_get_plat(dev); > struct mxc_uart *const uart = plat->reg; > > - if (!(readl(&uart->ts) & UTS_TXEMPTY)) > + if (readl(&uart->ts) & UTS_TXFULL) > return -EAGAIN; > > writel(ch, &uart->txd); > -- > 2.34.1 > Hello! In this driver there are two mxc_serial_putc() and two mxc_serial_getc() function. One for DM and one for non-DM version. It would be really nice to fix also second set of functions.
On Wed, 11 Jan 2023 at 00:55, Pali Rohár <pali@kernel.org> wrote: > > On Tuesday 10 January 2023 20:24:07 Loic Poulain wrote: > > Instead of waiting for empty FIFO condition before writing a > > character, wait for non-full FIFO condition. > > > > This helps in saving several tens of milliseconds during boot > > (depending verbosity). > > > > Signed-off-by: Loic Poulain <loic.poulain@linaro.org> > > Tested-by: Lothar Waßmann <LW@KARO-electronics.de> > > --- > > v2: fixing transfert abort & char corruption commit > > v3: Reordering commits for good bisectability > > > > drivers/serial/serial_mxc.c | 8 ++++---- > > 1 file changed, 4 insertions(+), 4 deletions(-) > > > > diff --git a/drivers/serial/serial_mxc.c b/drivers/serial/serial_mxc.c > > index 3c89781f2c..9899155c00 100644 > > --- a/drivers/serial/serial_mxc.c > > +++ b/drivers/serial/serial_mxc.c > > @@ -238,11 +238,11 @@ static void mxc_serial_putc(const char c) > > if (c == '\n') > > serial_putc('\r'); > > > > - writel(c, &mxc_base->txd); > > - > > /* wait for transmitter to be ready */ > > - while (!(readl(&mxc_base->ts) & UTS_TXEMPTY)) > > + while (readl(&mxc_base->ts) & UTS_TXFULL) > > schedule(); > > + > > + writel(c, &mxc_base->txd); > > } > > > > /* Test whether a character is in the RX buffer */ > > @@ -333,7 +333,7 @@ static int mxc_serial_putc(struct udevice *dev, const char ch) > > struct mxc_serial_plat *plat = dev_get_plat(dev); > > struct mxc_uart *const uart = plat->reg; > > > > - if (!(readl(&uart->ts) & UTS_TXEMPTY)) > > + if (readl(&uart->ts) & UTS_TXFULL) > > return -EAGAIN; > > > > writel(ch, &uart->txd); > > -- > > 2.34.1 > > > > Hello! > > In this driver there are two mxc_serial_putc() and two mxc_serial_getc() > function. One for DM and one for non-DM version. It would be really nice > to fix also second set of functions. This commit changes both DM/non-DM putc() functions. Regards, Loic
On Wednesday 11 January 2023 08:54:49 Loic Poulain wrote: > On Wed, 11 Jan 2023 at 00:55, Pali Rohár <pali@kernel.org> wrote: > > > > On Tuesday 10 January 2023 20:24:07 Loic Poulain wrote: > > > Instead of waiting for empty FIFO condition before writing a > > > character, wait for non-full FIFO condition. > > > > > > This helps in saving several tens of milliseconds during boot > > > (depending verbosity). > > > > > > Signed-off-by: Loic Poulain <loic.poulain@linaro.org> > > > Tested-by: Lothar Waßmann <LW@KARO-electronics.de> > > > --- > > > v2: fixing transfert abort & char corruption commit > > > v3: Reordering commits for good bisectability > > > > > > drivers/serial/serial_mxc.c | 8 ++++---- > > > 1 file changed, 4 insertions(+), 4 deletions(-) > > > > > > diff --git a/drivers/serial/serial_mxc.c b/drivers/serial/serial_mxc.c > > > index 3c89781f2c..9899155c00 100644 > > > --- a/drivers/serial/serial_mxc.c > > > +++ b/drivers/serial/serial_mxc.c > > > @@ -238,11 +238,11 @@ static void mxc_serial_putc(const char c) > > > if (c == '\n') > > > serial_putc('\r'); > > > > > > - writel(c, &mxc_base->txd); > > > - > > > /* wait for transmitter to be ready */ > > > - while (!(readl(&mxc_base->ts) & UTS_TXEMPTY)) > > > + while (readl(&mxc_base->ts) & UTS_TXFULL) > > > schedule(); > > > + > > > + writel(c, &mxc_base->txd); > > > } > > > > > > /* Test whether a character is in the RX buffer */ > > > @@ -333,7 +333,7 @@ static int mxc_serial_putc(struct udevice *dev, const char ch) > > > struct mxc_serial_plat *plat = dev_get_plat(dev); > > > struct mxc_uart *const uart = plat->reg; > > > > > > - if (!(readl(&uart->ts) & UTS_TXEMPTY)) > > > + if (readl(&uart->ts) & UTS_TXFULL) > > > return -EAGAIN; > > > > > > writel(ch, &uart->txd); > > > -- > > > 2.34.1 > > > > > > > Hello! > > > > In this driver there are two mxc_serial_putc() and two mxc_serial_getc() > > function. One for DM and one for non-DM version. It would be really nice > > to fix also second set of functions. > > This commit changes both DM/non-DM putc() functions. > > Regards, > Loic Ou, sorry for that. I have misread getc and putc strings, looks very similar for me. So it should be fine! Acked-by: Pali Rohár <pali@kernel.org>
diff --git a/drivers/serial/serial_mxc.c b/drivers/serial/serial_mxc.c index 3c89781f2c..9899155c00 100644 --- a/drivers/serial/serial_mxc.c +++ b/drivers/serial/serial_mxc.c @@ -238,11 +238,11 @@ static void mxc_serial_putc(const char c) if (c == '\n') serial_putc('\r'); - writel(c, &mxc_base->txd); - /* wait for transmitter to be ready */ - while (!(readl(&mxc_base->ts) & UTS_TXEMPTY)) + while (readl(&mxc_base->ts) & UTS_TXFULL) schedule(); + + writel(c, &mxc_base->txd); } /* Test whether a character is in the RX buffer */ @@ -333,7 +333,7 @@ static int mxc_serial_putc(struct udevice *dev, const char ch) struct mxc_serial_plat *plat = dev_get_plat(dev); struct mxc_uart *const uart = plat->reg; - if (!(readl(&uart->ts) & UTS_TXEMPTY)) + if (readl(&uart->ts) & UTS_TXFULL) return -EAGAIN; writel(ch, &uart->txd);