Re: [PATCH v5 4/4] mmc: mtk-sd: Protect crypto capability with crypto config

On 7/31/2026 12:40 AM, Eric Biggers wrote:
> On Thu, Jul 30, 2026 at 07:38:22PM +0530, Neeraj Soni wrote:
>> Host crypto capability can not be used if CONFIG_MMC_CRYPTO=n.
>> So set MMC_CAP2_CRYPTO in mmc->caps2 only if CONFIG_MMC_CRYPTO=y.
>>
>> Signed-off-by: Neeraj Soni <[email protected]>
>> ---
>>  drivers/mmc/host/mtk-sd.c | 4 ++++
>>  1 file changed, 4 insertions(+)
>>
>> diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
>> index 01ea3adbdf3b..c415ed97e3c2 100644
>> --- a/drivers/mmc/host/mtk-sd.c
>> +++ b/drivers/mmc/host/mtk-sd.c
>> @@ -3031,7 +3031,11 @@ static int msdc_drv_probe(struct platform_device *pdev)
>>  		if (IS_ERR(host->crypto_clk))
>>  			return PTR_ERR(host->crypto_clk);
>>  		else if (host->crypto_clk)
>> +#ifdef CONFIG_MMC_CRYPTO
>>  			mmc->caps2 |= MMC_CAP2_CRYPTO;
>> +#else
>> +			dev_dbg(host->dev, "Enable necessary crypto config\n");
>> +#endif
> 
> host->dev is still NULL at this point.  So if the log message were to be
> actually reached it would show '(NULL device *)'.
> 
> But the message doesn't seem very useful anyway, especially when it's
> logged only at debug level.  So maybe just drop it.
> 
> Is there a reason to even enable the crypto clock when CONFIG_MMC_CRYPTO
> is disabled?  If no, then the 'if' condition above could just be changed
> to:
> 
>     if (IS_ENABLED(CONFIG_MMC_CRYPTO) && !(mmc->caps2 & MMC_CAP2_NO_MMC)) {
>
We will not need this patch if the i revert the change made around
MMC_CAP2_CRYPTO here https://lore.kernel.org/linux-mmc/[email protected]/
since that change was not related to this series anyway. Will fix this
in v6.
 
> - Eric
> 
Regards,
Neeraj