Re: [PATCH] soc/tegra: fuse: Add clock error check in tegra_fuse_readl

[Nagarjuna Kristam <nkristam@nvidia.com>]

On 02-09-2019 16:15, Jon Hunter wrote:
> 
> On 28/08/2019 12:18, Nagarjuna Kristam wrote:
>> Tegra fuse clock handle is retrieved in tegra_fuse_probe().
>> tegra_fuse_readl() is exported symbol, which can be called from drivers
>> at any time. tegra_fuse_readl() enables fuse clock and reads corresponding
>> fuse register offset.
>>
>> Calling tegra_fuse_readl() before tegra_fuse_probe(), will cause data
>> abort. Add DEFER_PROBE error check for fuse clock in tegra_fuse_readl(),
>> to avoid enabling of fuse clock, before clock is available.
>>
>> Signed-off-by: Nagarjuna Kristam <nkristam@nvidia.com>
>> ---
>>  drivers/soc/tegra/fuse/fuse-tegra.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/soc/tegra/fuse/fuse-tegra.c b/drivers/soc/tegra/fuse/fuse-tegra.c
>> index 3eb44e6..21b39b7 100644
>> --- a/drivers/soc/tegra/fuse/fuse-tegra.c
>> +++ b/drivers/soc/tegra/fuse/fuse-tegra.c
>> @@ -186,7 +186,7 @@ u32 __init tegra_fuse_read_early(unsigned int offset)
>>  
>>  int tegra_fuse_readl(unsigned long offset, u32 *value)
>>  {
>> -	if (!fuse->read)
>> +	if (!fuse->read || (PTR_ERR(fuse->clk) == -EPROBE_DEFER))
>>  		return -EPROBE_DEFER;
> 
> What about the case where fuse->clk is NULL or a different error value?
> 
> Jon
> 
Yes, all error checks are needed, will use IS_ERR as a separate condition for clock.

Thanks,
Nagarjuna