> -----Original Message-----
> From: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>
> Sent: Thursday, July 14, 2022 9:31 AM
> To: Shenwei Wang <shenwei.wang@xxxxxxx>
> Cc: linux-serial@xxxxxxxxxxxxxxx
> Subject: [EXT] Re: [PATCH V1 1/1] serial: fsl_lpuart: zero out parity bit in CS7
> mode
>
> Caution: EXT Email
>
> On Fri, Jul 08, 2022 at 02:58:00PM -0500, shenwei.wang@xxxxxxx wrote:
> > The LPUART hardware doesn't zero out the parity bit on the received
> > characters. This behavior won't impact the use cases of CS8 because
> > the parity bit is the 9th bit which is not currently used by software.
> > But the parity bit for CS7 must be zeroed out by software in order to
> > get the correct raw data.
> >
> > Signed-off-by: Shenwei Wang <shenwei.wang@xxxxxxx>
> > ---
> > changes in v1
> > - fix the code indent and whitespace issue;
>
> Normal patches start numbering at v1 :)
>
> > drivers/tty/serial/fsl_lpuart.c | 26 ++++++++++++++++++++++++--
> > 1 file changed, 24 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/tty/serial/fsl_lpuart.c
> > b/drivers/tty/serial/fsl_lpuart.c index 8fe0494d4057b..a8f59fb27c825
> > 100644
> > --- a/drivers/tty/serial/fsl_lpuart.c
> > +++ b/drivers/tty/serial/fsl_lpuart.c
> > @@ -274,6 +274,8 @@ struct lpuart_port {
> > int rx_dma_rng_buf_len;
> > unsigned int dma_tx_nents;
> > wait_queue_head_t dma_wait;
> > + bool is_cs7; /* Set to true when character size is 7 */
> > + /* and the parity is enabled */
> > };
> >
> > struct lpuart_soc_data {
> > @@ -1022,6 +1024,9 @@ static void lpuart32_rxint(struct lpuart_port *sport)
> > flg = TTY_OVERRUN;
> > }
> >
> > + if (sport->is_cs7)
> > + rx &= 0x7F;
> > +
> > if (tty_insert_flip_char(port, rx, flg) == 0)
> > sport->port.icount.buf_overrun++;
> > }
> > @@ -1107,6 +1112,17 @@ static void lpuart_handle_sysrq(struct lpuart_port
> *sport)
> > }
> > }
> >
> > +static inline int lpuart_tty_insert_flip_string(struct tty_port *port,
> > + unsigned char *chars, size_t size, bool is_cs7)
>
> Why inline? Don't do that unless it is measurable with and without it, good
> compilers will guess this correctly.
Agree. The inline is not necessary here. Will fix it in next version.
Thanks,
Shenwei
> thanks,
>
> greg k-h
