[U-Boot] [PATCH] spi: zynq_spi: Fix infinite looping while xfer

From: Jagan Teki <jagannadh.teki@gmail.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH] spi: zynq_spi: Fix infinite looping while xfer
Date: Sat, 23 Jul 2016 21:49:09 +0530	[thread overview]
Message-ID: <CAD6G_RR3PrzJ3S3HNCE7fKeAoak-NW8J1ffijfRg2VgXMa5SxA@mail.gmail.com> (raw)
In-Reply-To: <CA+V-a8tnQptxBNak50HHD_24-2+N-N_=+LwnQp6gepW68tvpFQ@mail.gmail.com>

On 23 June 2016 at 19:28, Lad, Prabhakar <prabhakar.csengg@gmail.com> wrote:
> During spi transfer, for example:
> sspi 1:1.0 8 ff
>
> the rx_len values will  be:
> rx_len = 0
> rx_len = 4294967295
>
> This caused a busy looping during xfer, this patch fixes it
> by adding a check while reading the rx fifo
>
> Signed-off-by: Lad, Prabhakar <Prabhakar.Lad@racelogic.co.uk>
> Cc: Michal Simek <michal.simek@xilinx.com>
> Cc: Siva Durga Prasad Paladugu <sivadur@xilinx.com>
> Cc: Jagan Teki <jteki@openedev.com>
> ---
>  drivers/spi/zynq_spi.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/spi/zynq_spi.c b/drivers/spi/zynq_spi.c
> index 09ae1be..dd3de27 100644
> --- a/drivers/spi/zynq_spi.c
> +++ b/drivers/spi/zynq_spi.c
> @@ -230,7 +230,7 @@ static int zynq_spi_xfer(struct udevice *dev,
> unsigned int bitlen,
>
>          /* Read the data from RX FIFO */
>          status = readl(&regs->isr);
> -        while (status & ZYNQ_SPI_IXR_RXNEMPTY_MASK) {
> +        while ((status & ZYNQ_SPI_IXR_RXNEMPTY_MASK) && rx_len) {

Do post-decrement directly on while.

thanks!
-- 
Jagan.