Re: [PATCH] twl4030: Add some error checking to twl4030 init

[David Brownell <david-b@pacbell.net>]

On Monday 20 April 2009, Amit Kucheria wrote:
> Whitespace-fixed version and passed through checkpatch.pl
> 
> Check for return values of i2c read/write operations and size of scripts being
> uploaded to TWL4030
> 
> Signed-off-by: Amit Kucheria <amit.kucheria@verdurent.com>
> ---
>  drivers/mfd/twl4030-core.c  |    2 +-
>  drivers/mfd/twl4030-power.c |   49 ++++++++++++++++++++++++++++++------------


The changes look OK ... but what this needs is to be
split into two patches.  The -core one should go to
mainline; it's trivial, comment-only, unrelated to the
$SUBJECT patch.  The -power one seems OK for merge to
the OMAP tree.

(Of course, the -power driver should probably go mainline
at some point.  Once it stops breaking warm-reset!)


>  2 files changed, 36 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/mfd/twl4030-core.c b/drivers/mfd/twl4030-core.c
> index 769b34b..067b02e 100644
> --- a/drivers/mfd/twl4030-core.c
> +++ b/drivers/mfd/twl4030-core.c
> @@ -358,7 +358,7 @@ EXPORT_SYMBOL(twl4030_i2c_read);
>  int twl4030_i2c_write_u8(u8 mod_no, u8 value, u8 reg)
>  {
>  
> -	/* 2 bytes offset 1 contains the data offset 0 is used by i2c_write */
> +	/* 2 bytes: offset 1 contains the data, offset 0 is used by i2c_write */
>  	u8 temp_buffer[2] = { 0 };
>  	/* offset 1 contains the data */
>  	temp_buffer[1] = value;
> diff --git a/drivers/mfd/twl4030-power.c b/drivers/mfd/twl4030-power.c
> index 9dc493b..b4b636d 100644
> --- a/drivers/mfd/twl4030-power.c
> +++ b/drivers/mfd/twl4030-power.c
> @@ -257,36 +257,38 @@ static int __init config_warmreset_sequence(u8 address)
>  	return err;
>  }
>  
> -void twl4030_configure_resource(struct twl4030_resconfig *rconfig)
> +static int __init twl4030_configure_resource(struct twl4030_resconfig *rconfig)
>  {
>  	int rconfig_addr;
> +	int err;
>  	u8 type;
>  
>  	if (rconfig->resource > NUM_OF_RESOURCES) {
>  		printk(KERN_ERR
>  			"TWL4030 Resource %d does not exist\n",
>  			rconfig->resource);
> -		return;
> +		return -EINVAL;
>  	}
>  
>  	rconfig_addr = res_config_addrs[rconfig->resource];
>  
>  	/* Set resource group */
> -
>  	if (rconfig->devgroup >= 0)
> -		twl4030_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER,
> +		err = twl4030_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER,
>  					rconfig->devgroup << 5,
>  					rconfig_addr + DEVGROUP_OFFSET);
> +	if (err < 0) {
> +		printk(KERN_ERR "TWL4030 failed to program devgroup");
> +		return err;
> +	}
>  
>  	/* Set resource types */
> -
> -	if (twl4030_i2c_read_u8(TWL4030_MODULE_PM_RECEIVER,
> -					&type,
> -					rconfig_addr + TYPE_OFFSET) < 0) {
> -		printk(KERN_ERR
> -			"TWL4030 Resource %d type could not read\n",
> +	err = twl4030_i2c_read_u8(TWL4030_MODULE_PM_RECEIVER, &type,
> +				  rconfig_addr + TYPE_OFFSET);
> +	if (err < 0) {
> +		printk(KERN_ERR "TWL4030 Resource %d type could not be read\n",
>  			rconfig->resource);
> -		return;
> +		return err;
>  	}
>  
>  	if (rconfig->type >= 0) {
> @@ -299,8 +301,14 @@ void twl4030_configure_resource(struct twl4030_resconfig *rconfig)
>  		type |= rconfig->type2 << 3;
>  	}
>  
> -	twl4030_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER,
> +	err = twl4030_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER,
>  				type, rconfig_addr + TYPE_OFFSET);
> +	if (err < 0) {
> +		printk(KERN_ERR "TWL4030 failed to program resource type");
> +		return err;
> +	}
> +
> +	return 0;
>  
>  }
>  
> @@ -309,6 +317,12 @@ static int __init load_triton_script(struct twl4030_script *tscript)
>  	u8 address = triton_next_free_address;
>  	int err;
>  
> +	/* Make sure the script isn't going beyond last valid address */
> +	if ((address + tscript->size) > (END_OF_SCRIPT-1)) {
> +		printk(KERN_ERR "TWL4030 script too big error\n");
> +		return -EINVAL;
> +	}
> +
>  	err = twl4030_write_script(address, tscript->script, tscript->size);
>  	if (err)
>  		return err;
> @@ -346,15 +360,22 @@ void __init twl4030_power_init(struct twl4030_power_data *triton2_scripts)
>  
>  	for (i = 0; i < triton2_scripts->size; i++) {
>  		err = load_triton_script(triton2_scripts->scripts[i]);
> -		if (err)
> +		if (err < 0) {
> +			printk(KERN_ERR "TWL4030 failed to load scripts");
>  			break;
> +		}
>  	}
>  
>  	resconfig = triton2_scripts->resource_config;
>  	if (resconfig) {
>  		while (resconfig->resource) {
> -			twl4030_configure_resource(resconfig);
> +			err = twl4030_configure_resource(resconfig);
>  			resconfig++;
> +			if (err < 0) {
> +				printk(KERN_ERR
> +					"TWL4030 failed to configure resource");
> +				break;
> +			}
>  		}
>  	}
>  
> -- 
> 1.6.0.4
> 
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