[U-Boot] [PATCH 1/2] spi: fix mxc_spi_slave structure allocation to clear memory

[stefano babic]

Am 17/08/2012 20:15, schrieb Matt Sealey:
> Use calloc() instead of malloc() to allocate the mxc_spi_slave structure.
> Clearing the memory is necessary since most of the time this gets done
> super early in boot, but on warm reboots, and when SPI probing is done
> long after the init stages it could actually pick up previously used memory,
> and things like the chipselect polarity and other data end up being filled
> with trash data if not explicitly set by the board files.
> 
> This solves a semi-random, almost unreproducable error whereby SPI devices
> act very, very strangly on boot. Tested on Efika MX over several years..
> 
> Signed-off-by: Matt Sealey <matt at genesi-usa.com>
> ---
>  drivers/spi/mxc_spi.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/spi/mxc_spi.c b/drivers/spi/mxc_spi.c
> index 2e15318..d1dab18 100644
> --- a/drivers/spi/mxc_spi.c
> +++ b/drivers/spi/mxc_spi.c
> @@ -408,7 +408,7 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
>  	if (bus >= ARRAY_SIZE(spi_bases))
>  		return NULL;
>  
> -	mxcs = malloc(sizeof(struct mxc_spi_slave));
> +	mxcs = calloc(sizeof(struct mxc_spi_slave), 1);
>  	if (!mxcs) {
>  		puts("mxc_spi: SPI Slave not allocated !\n");
>  		return NULL;
> 

Agree, the structure must be zeroed.

Acked-by: Stefano Babic <sbabic at denx.de>

Best regards,
Stefano Babic


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