diff mbox

[U-Boot,2/2] spi: fix mxs_spi_slave structure allocation to clear memory

Message ID 1345227311-11433-2-git-send-email-matt@genesi-usa.com
State Accepted
Commit c6b52c4927df227c94650122363b8b342ddb62f0
Delegated to: Stefano Babic
Headers show

Commit Message

Matt Sealey Aug. 17, 2012, 6:15 p.m. UTC
Use calloc() instead of malloc() to allocate the mxs_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.

Signed-off-by: Matt Sealey <matt@genesi-usa.com>
---
 drivers/spi/mxs_spi.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Stefano Babic Aug. 18, 2012, 9:05 a.m. UTC | #1
Am 17/08/2012 20:15, schrieb Matt Sealey:
> Use calloc() instead of malloc() to allocate the mxs_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.
> 
> Signed-off-by: Matt Sealey <matt@genesi-usa.com>
> ---
>  drivers/spi/mxs_spi.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/spi/mxs_spi.c b/drivers/spi/mxs_spi.c
> index a037c13..5fa7f2b 100644
> --- a/drivers/spi/mxs_spi.c
> +++ b/drivers/spi/mxs_spi.c
> @@ -91,7 +91,7 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
>  		return NULL;
>  	}
>  
> -	mxs_slave = malloc(sizeof(struct mxs_spi_slave));
> +	mxs_slave = calloc(sizeof(struct mxs_spi_slave), 1);
>  	if (!mxs_slave)
>  		return NULL;
>  
> 


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

Best regards,
Stefano Babic
Stefano Babic Aug. 20, 2012, 7:59 a.m. UTC | #2
On 17/08/2012 20:15, Matt Sealey wrote:
> Use calloc() instead of malloc() to allocate the mxs_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.
> 
> Signed-off-by: Matt Sealey <matt@genesi-usa.com>
> ---
>  drivers/spi/mxs_spi.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/spi/mxs_spi.c b/drivers/spi/mxs_spi.c
> index a037c13..5fa7f2b 100644
> --- a/drivers/spi/mxs_spi.c
> +++ b/drivers/spi/mxs_spi.c
> @@ -91,7 +91,7 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
>  		return NULL;
>  	}
>  
> -	mxs_slave = malloc(sizeof(struct mxs_spi_slave));
> +	mxs_slave = calloc(sizeof(struct mxs_spi_slave), 1);
>  	if (!mxs_slave)
>  		return NULL;
>  
> 

Applied to u-boot-imx, thanks.

Best regards,
Stefano Babic
diff mbox

Patch

diff --git a/drivers/spi/mxs_spi.c b/drivers/spi/mxs_spi.c
index a037c13..5fa7f2b 100644
--- a/drivers/spi/mxs_spi.c
+++ b/drivers/spi/mxs_spi.c
@@ -91,7 +91,7 @@  struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
 		return NULL;
 	}
 
-	mxs_slave = malloc(sizeof(struct mxs_spi_slave));
+	mxs_slave = calloc(sizeof(struct mxs_spi_slave), 1);
 	if (!mxs_slave)
 		return NULL;