The driver uses two TIOCMBIT macros inside pl011_{get,set}_mctrl to
simplify the logic. Those look scary to checkpatch because they contain
ifs without do-while loops.
Avoid the macros by creating small equivalent static functions; that
lets the compiler do its type checking & avoids checkpatch errors.
For the second instance __assign_bit is not usable because it deals with
unsigned long pointers whereas we have an unsigned int in
pl011_set_mctrl.
Signed-off-by: Théo Lebrun <[email protected]>
---
drivers/tty/serial/amba-pl011.c | 46 +++++++++++++++++++++--------------------
1 file changed, 24 insertions(+), 22 deletions(-)
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 0d53973374de..bb3082c4d35c 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -1087,7 +1087,6 @@ static void pl011_dma_rx_poll(struct timer_list *t)
*/
if (jiffies_to_msecs(jiffies - dmarx->last_jiffies)
> uap->dmarx.poll_timeout) {
-
spin_lock_irqsave(&uap->port.lock, flags);
pl011_dma_rx_stop(uap);
uap->im |= UART011_RXIM;
@@ -1595,6 +1594,12 @@ static unsigned int pl011_tx_empty(struct uart_port *port)
0 : TIOCSER_TEMT;
}
+static void pl011_maybe_set_bit(bool cond, unsigned int *ptr, unsigned int mask)
+{
+ if (cond)
+ *ptr |= mask;
+}
+
static unsigned int pl011_get_mctrl(struct uart_port *port)
{
struct uart_amba_port *uap =
@@ -1602,18 +1607,22 @@ static unsigned int pl011_get_mctrl(struct uart_port *port)
unsigned int result = 0;
unsigned int status = pl011_read(uap, REG_FR);
-#define TIOCMBIT(uartbit, tiocmbit) \
- if (status & uartbit) \
- result |= tiocmbit
+ pl011_maybe_set_bit(status & UART01x_FR_DCD, &result, TIOCM_CAR);
+ pl011_maybe_set_bit(status & uap->vendor->fr_dsr, &result, TIOCM_DSR);
+ pl011_maybe_set_bit(status & uap->vendor->fr_cts, &result, TIOCM_CTS);
+ pl011_maybe_set_bit(status & uap->vendor->fr_ri, &result, TIOCM_RNG);
- TIOCMBIT(UART01x_FR_DCD, TIOCM_CAR);
- TIOCMBIT(uap->vendor->fr_dsr, TIOCM_DSR);
- TIOCMBIT(uap->vendor->fr_cts, TIOCM_CTS);
- TIOCMBIT(uap->vendor->fr_ri, TIOCM_RNG);
-#undef TIOCMBIT
return result;
}
+static void pl011_assign_bit(bool cond, unsigned int *ptr, unsigned int mask)
+{
+ if (cond)
+ *ptr |= mask;
+ else
+ *ptr &= ~mask;
+}
+
static void pl011_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
struct uart_amba_port *uap =
@@ -1622,23 +1631,16 @@ static void pl011_set_mctrl(struct uart_port *port, unsigned int mctrl)
cr = pl011_read(uap, REG_CR);
-#define TIOCMBIT(tiocmbit, uartbit) \
- if (mctrl & tiocmbit) \
- cr |= uartbit; \
- else \
- cr &= ~uartbit
-
- TIOCMBIT(TIOCM_RTS, UART011_CR_RTS);
- TIOCMBIT(TIOCM_DTR, UART011_CR_DTR);
- TIOCMBIT(TIOCM_OUT1, UART011_CR_OUT1);
- TIOCMBIT(TIOCM_OUT2, UART011_CR_OUT2);
- TIOCMBIT(TIOCM_LOOP, UART011_CR_LBE);
+ pl011_assign_bit(mctrl & TIOCM_RTS, &cr, UART011_CR_RTS);
+ pl011_assign_bit(mctrl & TIOCM_DTR, &cr, UART011_CR_DTR);
+ pl011_assign_bit(mctrl & TIOCM_OUT1, &cr, UART011_CR_OUT1);
+ pl011_assign_bit(mctrl & TIOCM_OUT2, &cr, UART011_CR_OUT2);
+ pl011_assign_bit(mctrl & TIOCM_LOOP, &cr, UART011_CR_LBE);
if (port->status & UPSTAT_AUTORTS) {
/* We need to disable auto-RTS if we want to turn RTS off */
- TIOCMBIT(TIOCM_RTS, UART011_CR_RTSEN);
+ pl011_assign_bit(mctrl & TIOCM_RTS, &cr, UART011_CR_RTSEN);
}
-#undef TIOCMBIT
pl011_write(cr, uap, REG_CR);
}
--
2.41.0
On Thu, Oct 26, 2023 at 12:41 PM Théo Lebrun <[email protected]> wrote:
> The driver uses two TIOCMBIT macros inside pl011_{get,set}_mctrl to
> simplify the logic. Those look scary to checkpatch because they contain
> ifs without do-while loops.
>
> Avoid the macros by creating small equivalent static functions; that
> lets the compiler do its type checking & avoids checkpatch errors.
>
> For the second instance __assign_bit is not usable because it deals with
> unsigned long pointers whereas we have an unsigned int in
> pl011_set_mctrl.
>
> Signed-off-by: Théo Lebrun <[email protected]>
The kernel looks better after this patch than before, so:
Reviewed-by: Linus Walleij <[email protected]>
Since the eternal defines uses masks rather than bits we can't
use __set_bit() & friends in this case and that's life.
Yours,
Linus Walleij
On Thu, 26 Oct 2023 12:41:21 +0200
Th?o Lebrun <[email protected]> wrote:
Hi,
> The driver uses two TIOCMBIT macros inside pl011_{get,set}_mctrl to
> simplify the logic. Those look scary to checkpatch because they contain
> ifs without do-while loops.
>
> Avoid the macros by creating small equivalent static functions; that
> lets the compiler do its type checking & avoids checkpatch errors.
>
> For the second instance __assign_bit is not usable because it deals with
> unsigned long pointers whereas we have an unsigned int in
> pl011_set_mctrl.
>
> Signed-off-by: Th?o Lebrun <[email protected]>
> ---
> drivers/tty/serial/amba-pl011.c | 46 +++++++++++++++++++++--------------------
> 1 file changed, 24 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
> index 0d53973374de..bb3082c4d35c 100644
> --- a/drivers/tty/serial/amba-pl011.c
> +++ b/drivers/tty/serial/amba-pl011.c
> @@ -1087,7 +1087,6 @@ static void pl011_dma_rx_poll(struct timer_list *t)
> */
> if (jiffies_to_msecs(jiffies - dmarx->last_jiffies)
> > uap->dmarx.poll_timeout) {
> -
This should go into a separate patch, or simply be merged with one
of your other coding style/whitespace cleanup patches.
Hugo.
> spin_lock_irqsave(&uap->port.lock, flags);
> pl011_dma_rx_stop(uap);
> uap->im |= UART011_RXIM;
> @@ -1595,6 +1594,12 @@ static unsigned int pl011_tx_empty(struct uart_port *port)
> 0 : TIOCSER_TEMT;
> }
>
> +static void pl011_maybe_set_bit(bool cond, unsigned int *ptr, unsigned int mask)
> +{
> + if (cond)
> + *ptr |= mask;
> +}
> +
> static unsigned int pl011_get_mctrl(struct uart_port *port)
> {
> struct uart_amba_port *uap =
> @@ -1602,18 +1607,22 @@ static unsigned int pl011_get_mctrl(struct uart_port *port)
> unsigned int result = 0;
> unsigned int status = pl011_read(uap, REG_FR);
>
> -#define TIOCMBIT(uartbit, tiocmbit) \
> - if (status & uartbit) \
> - result |= tiocmbit
> + pl011_maybe_set_bit(status & UART01x_FR_DCD, &result, TIOCM_CAR);
> + pl011_maybe_set_bit(status & uap->vendor->fr_dsr, &result, TIOCM_DSR);
> + pl011_maybe_set_bit(status & uap->vendor->fr_cts, &result, TIOCM_CTS);
> + pl011_maybe_set_bit(status & uap->vendor->fr_ri, &result, TIOCM_RNG);
>
> - TIOCMBIT(UART01x_FR_DCD, TIOCM_CAR);
> - TIOCMBIT(uap->vendor->fr_dsr, TIOCM_DSR);
> - TIOCMBIT(uap->vendor->fr_cts, TIOCM_CTS);
> - TIOCMBIT(uap->vendor->fr_ri, TIOCM_RNG);
> -#undef TIOCMBIT
> return result;
> }
>
> +static void pl011_assign_bit(bool cond, unsigned int *ptr, unsigned int mask)
> +{
> + if (cond)
> + *ptr |= mask;
> + else
> + *ptr &= ~mask;
> +}
> +
> static void pl011_set_mctrl(struct uart_port *port, unsigned int mctrl)
> {
> struct uart_amba_port *uap =
> @@ -1622,23 +1631,16 @@ static void pl011_set_mctrl(struct uart_port *port, unsigned int mctrl)
>
> cr = pl011_read(uap, REG_CR);
>
> -#define TIOCMBIT(tiocmbit, uartbit) \
> - if (mctrl & tiocmbit) \
> - cr |= uartbit; \
> - else \
> - cr &= ~uartbit
> -
> - TIOCMBIT(TIOCM_RTS, UART011_CR_RTS);
> - TIOCMBIT(TIOCM_DTR, UART011_CR_DTR);
> - TIOCMBIT(TIOCM_OUT1, UART011_CR_OUT1);
> - TIOCMBIT(TIOCM_OUT2, UART011_CR_OUT2);
> - TIOCMBIT(TIOCM_LOOP, UART011_CR_LBE);
> + pl011_assign_bit(mctrl & TIOCM_RTS, &cr, UART011_CR_RTS);
> + pl011_assign_bit(mctrl & TIOCM_DTR, &cr, UART011_CR_DTR);
> + pl011_assign_bit(mctrl & TIOCM_OUT1, &cr, UART011_CR_OUT1);
> + pl011_assign_bit(mctrl & TIOCM_OUT2, &cr, UART011_CR_OUT2);
> + pl011_assign_bit(mctrl & TIOCM_LOOP, &cr, UART011_CR_LBE);
>
> if (port->status & UPSTAT_AUTORTS) {
> /* We need to disable auto-RTS if we want to turn RTS off */
> - TIOCMBIT(TIOCM_RTS, UART011_CR_RTSEN);
> + pl011_assign_bit(mctrl & TIOCM_RTS, &cr, UART011_CR_RTSEN);
> }
> -#undef TIOCMBIT
>
> pl011_write(cr, uap, REG_CR);
> }
>
> --
> 2.41.0
>
Hello,
On Thu Oct 26, 2023 at 4:24 PM CEST, Hugo Villeneuve wrote:
> On Thu, 26 Oct 2023 12:41:21 +0200
> Théo Lebrun <[email protected]> wrote:
> > The driver uses two TIOCMBIT macros inside pl011_{get,set}_mctrl to
> > simplify the logic. Those look scary to checkpatch because they contain
> > ifs without do-while loops.
> >
> > Avoid the macros by creating small equivalent static functions; that
> > lets the compiler do its type checking & avoids checkpatch errors.
> >
> > For the second instance __assign_bit is not usable because it deals with
> > unsigned long pointers whereas we have an unsigned int in
> > pl011_set_mctrl.
> >
> > Signed-off-by: Théo Lebrun <[email protected]>
> > ---
> > drivers/tty/serial/amba-pl011.c | 46 +++++++++++++++++++++--------------------
> > 1 file changed, 24 insertions(+), 22 deletions(-)
> >
> > diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
> > index 0d53973374de..bb3082c4d35c 100644
> > --- a/drivers/tty/serial/amba-pl011.c
> > +++ b/drivers/tty/serial/amba-pl011.c
> > @@ -1087,7 +1087,6 @@ static void pl011_dma_rx_poll(struct timer_list *t)
> > */
> > if (jiffies_to_msecs(jiffies - dmarx->last_jiffies)
> > > uap->dmarx.poll_timeout) {
> > -
>
> This should go into a separate patch, or simply be merged with one
> of your other coding style/whitespace cleanup patches.
Indeed, added to "tty: serial: amba-pl011: cleanup driver". Thanks.
Regards,
--
Théo Lebrun, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com