| Message ID | 20190814092924.13857-2-geert+renesas@glider.be (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/3] serial: atmel: Don't check for mctrl_gpio_to_gpiod() returning error | expand |
Hello, [adding the Atmel guys to Cc] On Wed, Aug 14, 2019 at 11:29:22AM +0200, Geert Uytterhoeven wrote: > Since commit 1d267ea6539f2663 ("serial: mctrl-gpio: simplify init > routine"), mctrl_gpio_init() returns failure if the assignment to any > member of the gpio array results in an error pointer. > Since commit c359522194593815 ("serial: mctrl_gpio: Avoid probe failures > in case of missing gpiolib"), mctrl_gpio_to_gpiod() returns NULL in the > !CONFIG_GPIOLIB case. > Hence there is no longer a need to check for mctrl_gpio_to_gpiod() > returning an error value. A simple NULL check is sufficient. > > This follows the spirit of commit 445df7ff3fd1a0a9 ("serial: mctrl-gpio: > drop usages of IS_ERR_OR_NULL") in the mctrl-gpio core. > > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> > --- > drivers/tty/serial/atmel_serial.c | 12 ++++-------- > 1 file changed, 4 insertions(+), 8 deletions(-) > > diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c > index 19a85d6fe3d20541..e9620a81166b7dc1 100644 > --- a/drivers/tty/serial/atmel_serial.c > +++ b/drivers/tty/serial/atmel_serial.c > @@ -303,32 +303,28 @@ static unsigned int atmel_get_lines_status(struct uart_port *port) > > mctrl_gpio_get(atmel_port->gpios, &ret); > > - if (!IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(atmel_port->gpios, > - UART_GPIO_CTS))) { > + if (mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_CTS)) { > if (ret & TIOCM_CTS) > status &= ~ATMEL_US_CTS; > else > status |= ATMEL_US_CTS; > } The change is fine, but it seems the atmel driver doesn't use mctrl_gpio as expected (at least as expected by me). IMHO driving the hardware function of the CTS pin shouldn't be conditional on the presence of a cts-gpio. Is there a reason not to just drop the if completely? Best regards Uwe
Hi Uwe, On Wed, Aug 14, 2019 at 11:36 AM Uwe Kleine-König <u.kleine-koenig@pengutronix.de> wrote: > On Wed, Aug 14, 2019 at 11:29:22AM +0200, Geert Uytterhoeven wrote: > > Since commit 1d267ea6539f2663 ("serial: mctrl-gpio: simplify init > > routine"), mctrl_gpio_init() returns failure if the assignment to any > > member of the gpio array results in an error pointer. > > Since commit c359522194593815 ("serial: mctrl_gpio: Avoid probe failures > > in case of missing gpiolib"), mctrl_gpio_to_gpiod() returns NULL in the > > !CONFIG_GPIOLIB case. > > Hence there is no longer a need to check for mctrl_gpio_to_gpiod() > > returning an error value. A simple NULL check is sufficient. > > > > This follows the spirit of commit 445df7ff3fd1a0a9 ("serial: mctrl-gpio: > > drop usages of IS_ERR_OR_NULL") in the mctrl-gpio core. > > > > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> > > --- > > drivers/tty/serial/atmel_serial.c | 12 ++++-------- > > 1 file changed, 4 insertions(+), 8 deletions(-) > > > > diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c > > index 19a85d6fe3d20541..e9620a81166b7dc1 100644 > > --- a/drivers/tty/serial/atmel_serial.c > > +++ b/drivers/tty/serial/atmel_serial.c > > @@ -303,32 +303,28 @@ static unsigned int atmel_get_lines_status(struct uart_port *port) > > > > mctrl_gpio_get(atmel_port->gpios, &ret); > > > > - if (!IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(atmel_port->gpios, > > - UART_GPIO_CTS))) { > > + if (mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_CTS)) { > > if (ret & TIOCM_CTS) > > status &= ~ATMEL_US_CTS; > > else > > status |= ATMEL_US_CTS; > > } > > The change is fine, but it seems the atmel driver doesn't use mctrl_gpio > as expected (at least as expected by me). IMHO driving the hardware > function of the CTS pin shouldn't be conditional on the presence of a > cts-gpio. Is there a reason not to just drop the if completely? The above code returns the hardware status if CTS is not a GPIO, and returns (overrides with) the GPIO status if CTS is a GPIO. Isn't that correct, or am I missing something? Gr{oetje,eeting}s, Geert
On Wed, Aug 14, 2019 at 12:20:33PM +0200, Geert Uytterhoeven wrote: > Hi Uwe, > > On Wed, Aug 14, 2019 at 11:36 AM Uwe Kleine-König > <u.kleine-koenig@pengutronix.de> wrote: > > On Wed, Aug 14, 2019 at 11:29:22AM +0200, Geert Uytterhoeven wrote: > > > Since commit 1d267ea6539f2663 ("serial: mctrl-gpio: simplify init > > > routine"), mctrl_gpio_init() returns failure if the assignment to any > > > member of the gpio array results in an error pointer. > > > Since commit c359522194593815 ("serial: mctrl_gpio: Avoid probe failures > > > in case of missing gpiolib"), mctrl_gpio_to_gpiod() returns NULL in the > > > !CONFIG_GPIOLIB case. > > > Hence there is no longer a need to check for mctrl_gpio_to_gpiod() > > > returning an error value. A simple NULL check is sufficient. > > > > > > This follows the spirit of commit 445df7ff3fd1a0a9 ("serial: mctrl-gpio: > > > drop usages of IS_ERR_OR_NULL") in the mctrl-gpio core. > > > > > > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> > > > --- > > > drivers/tty/serial/atmel_serial.c | 12 ++++-------- > > > 1 file changed, 4 insertions(+), 8 deletions(-) > > > > > > diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c > > > index 19a85d6fe3d20541..e9620a81166b7dc1 100644 > > > --- a/drivers/tty/serial/atmel_serial.c > > > +++ b/drivers/tty/serial/atmel_serial.c > > > @@ -303,32 +303,28 @@ static unsigned int atmel_get_lines_status(struct uart_port *port) > > > > > > mctrl_gpio_get(atmel_port->gpios, &ret); > > > > > > - if (!IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(atmel_port->gpios, > > > - UART_GPIO_CTS))) { > > > + if (mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_CTS)) { > > > if (ret & TIOCM_CTS) > > > status &= ~ATMEL_US_CTS; > > > else > > > status |= ATMEL_US_CTS; > > > } > > > > The change is fine, but it seems the atmel driver doesn't use mctrl_gpio > > as expected (at least as expected by me). IMHO driving the hardware > > function of the CTS pin shouldn't be conditional on the presence of a > > cts-gpio. Is there a reason not to just drop the if completely? > > The above code returns the hardware status if CTS is not a GPIO, and > returns (overrides with) the GPIO status if CTS is a GPIO. > Isn't that correct, or am I missing something? I took a deeper look into this driver now. The task for atmel_get_lines_status() isn't to implement the get_mctrl() callback. Instead this is called in the irqhandler to set ATMEL_US_RI in a "pending" value that then later in atmel_handle_status() is translated to a "ring" event that is handled there. So the right cleanup would be to let atmel_get_lines_status() just be return atmel_uart_readl(port, ATMEL_US_CSR); . If something happend on the lines implemented as gpio the driver's irq function isn't called anyhow. Best regards Uwe
Hi, Le 14/08/2019 à 12:20, Geert Uytterhoeven a écrit : > Hi Uwe, > > On Wed, Aug 14, 2019 at 11:36 AM Uwe Kleine-König > <u.kleine-koenig@pengutronix.de> wrote: >> On Wed, Aug 14, 2019 at 11:29:22AM +0200, Geert Uytterhoeven wrote: >>> Since commit 1d267ea6539f2663 ("serial: mctrl-gpio: simplify init >>> routine"), mctrl_gpio_init() returns failure if the assignment to any >>> member of the gpio array results in an error pointer. >>> Since commit c359522194593815 ("serial: mctrl_gpio: Avoid probe failures >>> in case of missing gpiolib"), mctrl_gpio_to_gpiod() returns NULL in the >>> !CONFIG_GPIOLIB case. >>> Hence there is no longer a need to check for mctrl_gpio_to_gpiod() >>> returning an error value. A simple NULL check is sufficient. >>> >>> This follows the spirit of commit 445df7ff3fd1a0a9 ("serial: mctrl-gpio: >>> drop usages of IS_ERR_OR_NULL") in the mctrl-gpio core. >>> >>> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> >>> --- >>> drivers/tty/serial/atmel_serial.c | 12 ++++-------- >>> 1 file changed, 4 insertions(+), 8 deletions(-) >>> >>> diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c >>> index 19a85d6fe3d20541..e9620a81166b7dc1 100644 >>> --- a/drivers/tty/serial/atmel_serial.c >>> +++ b/drivers/tty/serial/atmel_serial.c >>> @@ -303,32 +303,28 @@ static unsigned int atmel_get_lines_status(struct uart_port *port) >>> >>> mctrl_gpio_get(atmel_port->gpios, &ret); >>> >>> - if (!IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(atmel_port->gpios, >>> - UART_GPIO_CTS))) { >>> + if (mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_CTS)) { >>> if (ret & TIOCM_CTS) >>> status &= ~ATMEL_US_CTS; >>> else >>> status |= ATMEL_US_CTS; >>> } >> >> The change is fine, but it seems the atmel driver doesn't use mctrl_gpio >> as expected (at least as expected by me). IMHO driving the hardware >> function of the CTS pin shouldn't be conditional on the presence of a >> cts-gpio. Is there a reason not to just drop the if completely? > > The above code returns the hardware status if CTS is not a GPIO, and > returns (overrides with) the GPIO status if CTS is a GPIO. > Isn't that correct, or am I missing something? Yes, that's correct.
Le 14/08/2019 à 13:08, Uwe Kleine-König a écrit : > On Wed, Aug 14, 2019 at 12:20:33PM +0200, Geert Uytterhoeven wrote: >> Hi Uwe, >> >> On Wed, Aug 14, 2019 at 11:36 AM Uwe Kleine-König >> <u.kleine-koenig@pengutronix.de> wrote: >>> On Wed, Aug 14, 2019 at 11:29:22AM +0200, Geert Uytterhoeven wrote: >>>> Since commit 1d267ea6539f2663 ("serial: mctrl-gpio: simplify init >>>> routine"), mctrl_gpio_init() returns failure if the assignment to any >>>> member of the gpio array results in an error pointer. >>>> Since commit c359522194593815 ("serial: mctrl_gpio: Avoid probe failures >>>> in case of missing gpiolib"), mctrl_gpio_to_gpiod() returns NULL in the >>>> !CONFIG_GPIOLIB case. >>>> Hence there is no longer a need to check for mctrl_gpio_to_gpiod() >>>> returning an error value. A simple NULL check is sufficient. >>>> >>>> This follows the spirit of commit 445df7ff3fd1a0a9 ("serial: mctrl-gpio: >>>> drop usages of IS_ERR_OR_NULL") in the mctrl-gpio core. >>>> >>>> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> >>>> --- >>>> drivers/tty/serial/atmel_serial.c | 12 ++++-------- >>>> 1 file changed, 4 insertions(+), 8 deletions(-) >>>> >>>> diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c >>>> index 19a85d6fe3d20541..e9620a81166b7dc1 100644 >>>> --- a/drivers/tty/serial/atmel_serial.c >>>> +++ b/drivers/tty/serial/atmel_serial.c >>>> @@ -303,32 +303,28 @@ static unsigned int atmel_get_lines_status(struct uart_port *port) >>>> >>>> mctrl_gpio_get(atmel_port->gpios, &ret); >>>> >>>> - if (!IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(atmel_port->gpios, >>>> - UART_GPIO_CTS))) { >>>> + if (mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_CTS)) { >>>> if (ret & TIOCM_CTS) >>>> status &= ~ATMEL_US_CTS; >>>> else >>>> status |= ATMEL_US_CTS; >>>> } >>> >>> The change is fine, but it seems the atmel driver doesn't use mctrl_gpio >>> as expected (at least as expected by me). IMHO driving the hardware >>> function of the CTS pin shouldn't be conditional on the presence of a >>> cts-gpio. Is there a reason not to just drop the if completely? >> >> The above code returns the hardware status if CTS is not a GPIO, and >> returns (overrides with) the GPIO status if CTS is a GPIO. >> Isn't that correct, or am I missing something? > > I took a deeper look into this driver now. The task for > atmel_get_lines_status() isn't to implement the get_mctrl() callback. > > Instead this is called in the irqhandler to set ATMEL_US_RI in a > "pending" value that then later in atmel_handle_status() is translated > to a "ring" event that is handled there. > > So the right cleanup would be to let atmel_get_lines_status() just be > > return atmel_uart_readl(port, ATMEL_US_CSR); > > . If something happend on the lines implemented as gpio the driver's irq > function isn't called anyhow. I'd like to give it a good test to be sure, and I'll get back to you. Thanks, Richard
Le 20/08/2019 à 17:47, Richard Genoud a écrit : > Le 14/08/2019 à 13:08, Uwe Kleine-König a écrit : >> On Wed, Aug 14, 2019 at 12:20:33PM +0200, Geert Uytterhoeven wrote: >>> Hi Uwe, >>> >>> On Wed, Aug 14, 2019 at 11:36 AM Uwe Kleine-König >>> <u.kleine-koenig@pengutronix.de> wrote: >>>> On Wed, Aug 14, 2019 at 11:29:22AM +0200, Geert Uytterhoeven wrote: >>>>> Since commit 1d267ea6539f2663 ("serial: mctrl-gpio: simplify init >>>>> routine"), mctrl_gpio_init() returns failure if the assignment to any >>>>> member of the gpio array results in an error pointer. >>>>> Since commit c359522194593815 ("serial: mctrl_gpio: Avoid probe failures >>>>> in case of missing gpiolib"), mctrl_gpio_to_gpiod() returns NULL in the >>>>> !CONFIG_GPIOLIB case. >>>>> Hence there is no longer a need to check for mctrl_gpio_to_gpiod() >>>>> returning an error value. A simple NULL check is sufficient. >>>>> >>>>> This follows the spirit of commit 445df7ff3fd1a0a9 ("serial: mctrl-gpio: >>>>> drop usages of IS_ERR_OR_NULL") in the mctrl-gpio core. >>>>> >>>>> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> >>>>> --- >>>>> drivers/tty/serial/atmel_serial.c | 12 ++++-------- >>>>> 1 file changed, 4 insertions(+), 8 deletions(-) >>>>> >>>>> diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c >>>>> index 19a85d6fe3d20541..e9620a81166b7dc1 100644 >>>>> --- a/drivers/tty/serial/atmel_serial.c >>>>> +++ b/drivers/tty/serial/atmel_serial.c >>>>> @@ -303,32 +303,28 @@ static unsigned int atmel_get_lines_status(struct uart_port *port) >>>>> >>>>> mctrl_gpio_get(atmel_port->gpios, &ret); >>>>> >>>>> - if (!IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(atmel_port->gpios, >>>>> - UART_GPIO_CTS))) { >>>>> + if (mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_CTS)) { >>>>> if (ret & TIOCM_CTS) >>>>> status &= ~ATMEL_US_CTS; >>>>> else >>>>> status |= ATMEL_US_CTS; >>>>> } >>>> >>>> The change is fine, but it seems the atmel driver doesn't use mctrl_gpio >>>> as expected (at least as expected by me). IMHO driving the hardware >>>> function of the CTS pin shouldn't be conditional on the presence of a >>>> cts-gpio. Is there a reason not to just drop the if completely? >>> >>> The above code returns the hardware status if CTS is not a GPIO, and >>> returns (overrides with) the GPIO status if CTS is a GPIO. >>> Isn't that correct, or am I missing something? >> >> I took a deeper look into this driver now. The task for >> atmel_get_lines_status() isn't to implement the get_mctrl() callback. >> >> Instead this is called in the irqhandler to set ATMEL_US_RI in a >> "pending" value that then later in atmel_handle_status() is translated >> to a "ring" event that is handled there. >> >> So the right cleanup would be to let atmel_get_lines_status() just be >> >> return atmel_uart_readl(port, ATMEL_US_CSR); >> >> . If something happend on the lines implemented as gpio the driver's irq >> function isn't called anyhow. > > I'd like to give it a good test to be sure, and I'll get back to you. So, Uwe is right. Since commit ce59e48fdbad ("serial: mctrl_gpio: implement interrupt handling"), atmel_get_lines_status() can be completly killed and replaced by : atmel_uart_readl(port, ATMEL_US_CSR); Geert, do you want to send a patch for that, or should I do it ? Thanks, Richard
Hi Richard, On Wed, Aug 21, 2019 at 5:27 PM Richard Genoud <richard.genoud@gmail.com> wrote: > Le 20/08/2019 à 17:47, Richard Genoud a écrit : > > Le 14/08/2019 à 13:08, Uwe Kleine-König a écrit : > >> On Wed, Aug 14, 2019 at 12:20:33PM +0200, Geert Uytterhoeven wrote: > >>> Hi Uwe, > >>> > >>> On Wed, Aug 14, 2019 at 11:36 AM Uwe Kleine-König > >>> <u.kleine-koenig@pengutronix.de> wrote: > >>>> On Wed, Aug 14, 2019 at 11:29:22AM +0200, Geert Uytterhoeven wrote: > >>>>> Since commit 1d267ea6539f2663 ("serial: mctrl-gpio: simplify init > >>>>> routine"), mctrl_gpio_init() returns failure if the assignment to any > >>>>> member of the gpio array results in an error pointer. > >>>>> Since commit c359522194593815 ("serial: mctrl_gpio: Avoid probe failures > >>>>> in case of missing gpiolib"), mctrl_gpio_to_gpiod() returns NULL in the > >>>>> !CONFIG_GPIOLIB case. > >>>>> Hence there is no longer a need to check for mctrl_gpio_to_gpiod() > >>>>> returning an error value. A simple NULL check is sufficient. > >>>>> > >>>>> This follows the spirit of commit 445df7ff3fd1a0a9 ("serial: mctrl-gpio: > >>>>> drop usages of IS_ERR_OR_NULL") in the mctrl-gpio core. > >>>>> > >>>>> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> > >>>>> --- > >>>>> drivers/tty/serial/atmel_serial.c | 12 ++++-------- > >>>>> 1 file changed, 4 insertions(+), 8 deletions(-) > >>>>> > >>>>> diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c > >>>>> index 19a85d6fe3d20541..e9620a81166b7dc1 100644 > >>>>> --- a/drivers/tty/serial/atmel_serial.c > >>>>> +++ b/drivers/tty/serial/atmel_serial.c > >>>>> @@ -303,32 +303,28 @@ static unsigned int atmel_get_lines_status(struct uart_port *port) > >>>>> > >>>>> mctrl_gpio_get(atmel_port->gpios, &ret); > >>>>> > >>>>> - if (!IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(atmel_port->gpios, > >>>>> - UART_GPIO_CTS))) { > >>>>> + if (mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_CTS)) { > >>>>> if (ret & TIOCM_CTS) > >>>>> status &= ~ATMEL_US_CTS; > >>>>> else > >>>>> status |= ATMEL_US_CTS; > >>>>> } > >>>> > >>>> The change is fine, but it seems the atmel driver doesn't use mctrl_gpio > >>>> as expected (at least as expected by me). IMHO driving the hardware > >>>> function of the CTS pin shouldn't be conditional on the presence of a > >>>> cts-gpio. Is there a reason not to just drop the if completely? > >>> > >>> The above code returns the hardware status if CTS is not a GPIO, and > >>> returns (overrides with) the GPIO status if CTS is a GPIO. > >>> Isn't that correct, or am I missing something? > >> > >> I took a deeper look into this driver now. The task for > >> atmel_get_lines_status() isn't to implement the get_mctrl() callback. > >> > >> Instead this is called in the irqhandler to set ATMEL_US_RI in a > >> "pending" value that then later in atmel_handle_status() is translated > >> to a "ring" event that is handled there. > >> > >> So the right cleanup would be to let atmel_get_lines_status() just be > >> > >> return atmel_uart_readl(port, ATMEL_US_CSR); > >> > >> . If something happend on the lines implemented as gpio the driver's irq > >> function isn't called anyhow. > > > > I'd like to give it a good test to be sure, and I'll get back to you. > > So, Uwe is right. > Since commit ce59e48fdbad ("serial: mctrl_gpio: implement interrupt handling"), > atmel_get_lines_status() can be completly killed and replaced by : > atmel_uart_readl(port, ATMEL_US_CSR); > > Geert, do you want to send a patch for that, or should I do it ? Feel free to send a patch. I don't have the Atmel hardware anyway. Thanks! Gr{oetje,eeting}s, Geert
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c index 19a85d6fe3d20541..e9620a81166b7dc1 100644 --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -303,32 +303,28 @@ static unsigned int atmel_get_lines_status(struct uart_port *port) mctrl_gpio_get(atmel_port->gpios, &ret); - if (!IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(atmel_port->gpios, - UART_GPIO_CTS))) { + if (mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_CTS)) { if (ret & TIOCM_CTS) status &= ~ATMEL_US_CTS; else status |= ATMEL_US_CTS; } - if (!IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(atmel_port->gpios, - UART_GPIO_DSR))) { + if (mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_DSR)) { if (ret & TIOCM_DSR) status &= ~ATMEL_US_DSR; else status |= ATMEL_US_DSR; } - if (!IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(atmel_port->gpios, - UART_GPIO_RI))) { + if (mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_RI)) { if (ret & TIOCM_RI) status &= ~ATMEL_US_RI; else status |= ATMEL_US_RI; } - if (!IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(atmel_port->gpios, - UART_GPIO_DCD))) { + if (mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_DCD)) { if (ret & TIOCM_CD) status &= ~ATMEL_US_DCD; else
Since commit 1d267ea6539f2663 ("serial: mctrl-gpio: simplify init routine"), mctrl_gpio_init() returns failure if the assignment to any member of the gpio array results in an error pointer. Since commit c359522194593815 ("serial: mctrl_gpio: Avoid probe failures in case of missing gpiolib"), mctrl_gpio_to_gpiod() returns NULL in the !CONFIG_GPIOLIB case. Hence there is no longer a need to check for mctrl_gpio_to_gpiod() returning an error value. A simple NULL check is sufficient. This follows the spirit of commit 445df7ff3fd1a0a9 ("serial: mctrl-gpio: drop usages of IS_ERR_OR_NULL") in the mctrl-gpio core. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> --- drivers/tty/serial/atmel_serial.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-)