Re: [PATCH v2 2/3] scsi: ufs: Modulize ufs-bsg

[Bart Van Assche]

On 12/11/19 3:49 AM, Can Guo wrote:
> In order to improve the flexibility of ufs-bsg, modulizing it is a good
> choice. This change introduces tristate to ufs-bsg to allow users compile
> it as an external module.

Did you perhaps mean "modularize" instead of "modulize"? Additionally, 
should "modulizing" perhaps be changed into "modularizing"?

> diff --git a/drivers/scsi/ufs/Kconfig b/drivers/scsi/ufs/Kconfig
> index d14c224..72620ce 100644
> --- a/drivers/scsi/ufs/Kconfig
> +++ b/drivers/scsi/ufs/Kconfig
> @@ -38,6 +38,7 @@ config SCSI_UFSHCD
>   	select PM_DEVFREQ
>   	select DEVFREQ_GOV_SIMPLE_ONDEMAND
>   	select NLS
> +	select BLK_DEV_BSGLIB
>   	---help---
>   	This selects the support for UFS devices in Linux, say Y and make
>   	  sure that you know the name of your UFS host adapter (the card

I do not understand the above change. Doesn't moving the BSG code into a 
separate module remove the dependency of SCSI_UFSHCD on BLK_DEV_BSGLIB?

> +static int __init ufs_bsg_init(void)
> +{
> +	struct list_head *hba_list = NULL;
> +	struct ufs_hba *hba;
> +	int ret = 0;
> +
> +	ufshcd_get_hba_list_lock(&hba_list);
> +	list_for_each_entry(hba, hba_list, list) {
> +		ret = ufs_bsg_probe(hba);
> +		if (ret)
> +			break;
> +	}
> +	ufshcd_put_hba_list_unlock();
> +
> +	return ret;
> +}

What if ufs_bsg_probe() succeeds for some UFS adapters but not for 
others? Shouldn't ufs_bgs_remove() be called in that case for the 
adapters for which ufs_bsg_probe() succeeded?

> +late_initcall_sync(ufs_bsg_init);
> +module_exit(ufs_bsg_exit);

Why late_initcall_sync() instead of module_init()?

> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index a86b0fd..7a83a8f 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -108,6 +108,22 @@
>   		       16, 4, buf, __len, false);                        \
>   } while (0)
>   
> +static LIST_HEAD(ufs_hba_list);
> +static DEFINE_MUTEX(ufs_hba_list_lock);
> +
> +void ufshcd_get_hba_list_lock(struct list_head **list)
> +{
> +	mutex_lock(&ufs_hba_list_lock);
> +	*list = &ufs_hba_list;
> +}
> +EXPORT_SYMBOL_GPL(ufshcd_get_hba_list_lock);

Please make ufshcd_get_hba_list_lock() return the list_head pointer 
instead of the above.

Thanks,

Bart.