[PATCH v1] spi: dw: add check for Rx FIFO overflow

[Jagan Teki]

On Mon, Dec 18, 2023 at 11:01 PM Maxim Kiselev <bigunclemax at gmail.com> wrote:
>
> Hello Jagan,
>
> пн, 18 дек. 2023 г. в 14:28, Jagan Teki <jagan at amarulasolutions.com>:
> >
> > On Tue, Oct 17, 2023 at 12:35 PM Maksim Kiselev <bigunclemax at gmail.com> wrote:
> > >
> > > If even one byte is lost due to Rx FIFO overflow then we will never
> > > exit the read loop. Because the (priv->rx != priv->rx_end) condition will
> > > be always true.
> > >
> > > Let's check if Rx FIFO overflow occurred and exit the read loop
> > > in this case.
> > >
> > > Signed-off-by: Maksim Kiselev <bigunclemax at gmail.com>
> > > ---
> > >  drivers/spi/designware_spi.c | 24 +++++++++++++++++++++---
> > >  1 file changed, 21 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/drivers/spi/designware_spi.c b/drivers/spi/designware_spi.c
> > > index 1c7d0ca310..0f443bff8e 100644
> > > --- a/drivers/spi/designware_spi.c
> > > +++ b/drivers/spi/designware_spi.c
> > > @@ -111,6 +111,15 @@
> > >  #define SR_TX_ERR                      BIT(5)
> > >  #define SR_DCOL                                BIT(6)
> > >
> > > +/* Bit fields in ISR, IMR, RISR, 7 bits */
> > > +#define DW_SPI_INT_MASK                        GENMASK(5, 0)
> > > +#define DW_SPI_INT_TXEI                        BIT(0)
> > > +#define DW_SPI_INT_TXOI                        BIT(1)
> > > +#define DW_SPI_INT_RXUI                        BIT(2)
> > > +#define DW_SPI_INT_RXOI                        BIT(3)
> > > +#define DW_SPI_INT_RXFI                        BIT(4)
> > > +#define DW_SPI_INT_MSTI                        BIT(5)
> >
> > Why do we need unused macros?
>
> Actually DW_SPI_INT_RXOI is used. As for the other bits in DW_SPI_RISR,
> I decided to add them all to match a Linux driver.
>
> We already have a lot of unused macro in this driver (ex. definitions
> for bits in CTRLR0_FRF,
> CTRLR0_MODE regs and so on).
>
> So, what's a problem with adding the DW_SPI_RISR bits?

I'm not fond of unused change in the particular patch, better to send
the updated one with used bits.

Jagan.