[U-Boot] [PATCH 4/7] spi: altera: Zap endless loop

[Jagan Teki]

On 20 October 2014 00:13, Marek Vasut <marex at denx.de> wrote:
> The driver contained an endless loop when waiting for TX completion,
> this is a bad idea since if the hardware fails, the loop might spin
> forever. Add timeout and handle it.
>
> Signed-off-by: Marek Vasut <marex at denx.de>
> Cc: Chin Liang See <clsee at altera.com>
> Cc: Dinh Nguyen <dinguyen at altera.com>
> Cc: Albert Aribaud <albert.u.boot at aribaud.net>
> Cc: Tom Rini <trini at ti.com>
> Cc: Wolfgang Denk <wd at denx.de>
> Cc: Pavel Machek <pavel at denx.de>
> Cc: Jagannadha Sutradharudu Teki <jagannadh.teki at gmail.com>
> ---
>  drivers/spi/altera_spi.c | 14 ++++++++++++--
>  1 file changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/spi/altera_spi.c b/drivers/spi/altera_spi.c
> index 373ce30..ee65ec2 100644
> --- a/drivers/spi/altera_spi.c
> +++ b/drivers/spi/altera_spi.c
> @@ -129,6 +129,8 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
>         uint bytes = bitlen / 8;
>         const uchar *txp = dout;
>         uchar *rxp = din;
> +       int timeout = 10000;

This could be macro definable.

> +       uint32_t reg;
>
>         debug("%s: bus:%i cs:%i bitlen:%i bytes:%i flags:%lx\n", __func__,
>               slave->bus, slave->cs, bitlen, bytes, flags);
> @@ -154,8 +156,16 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
>                 debug("%s: tx:%x ", __func__, d);
>                 writel(d, &altspi->regs->txdata);
>
> -               while (!(readl(&altspi->regs->status) & ALTERA_SPI_STATUS_RRDY_MSK))
> -                       ;
> +               while (--timeout) {
> +                       reg = readl(&altspi->regs->status);
> +                       if (reg & ALTERA_SPI_STATUS_RRDY_MSK)
> +                               break;
> +               }
> +
> +               if (!timeout) {
> +                       printf("%s: Transmission timed out!\n", __func__);
> +                       goto done;
> +               }

It's better to use tx status check with the help of get_timer()
instead of normal while loop.
Pls-  use the same, we have some drivers who does the same.

>
>                 d = readl(&altspi->regs->rxdata);
>                 if (rxp)
> --
> 2.1.1
>

thanks!
-- 
Jagan.