Re: [RFC PATCH 02/13] scsi: ufshpb: Init part I - Read HPB config

[Bart Van Assche <bvanassche@acm.org>]

On 2020-05-15 03:30, Avri Altman wrote:
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 426073a..bffe699 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -50,6 +50,7 @@
>  #include "ufs_bsg.h"
>  #include <asm/unaligned.h>
>  #include <linux/blkdev.h>
> +#include "ufshpb.h"
>  
>  #define CREATE_TRACE_POINTS
>  #include <trace/events/ufs.h>
> @@ -7341,6 +7342,9 @@ static int ufshcd_add_lus(struct ufs_hba *hba)
>  		hba->clk_scaling.is_allowed = true;
>  	}
>  
> +	if (ufshcd_is_hpb_supported(hba))
> +		ufshpb_probe(hba);
> +
>  	ufs_bsg_probe(hba);
>  	scsi_scan_host(hba->host);
>  	pm_runtime_put_sync(hba->dev);

This looks weird to me because of the following reasons:
- If there are direct calls from the ufshcd module into the ufshpb
  module and if there are direct calls from the ufshpb module into the
  ufshcd module, why has ufshpb been implemented as a kernel module? Or
  in other words, will it ever be possible to load the ufshcd module
  without loading the ufshpb module?
- Patch 3/13 makes ufshpb a device handler. There are no direct calls
  from any upstream SCSI LLD to any upstream device handler. However,
  this patch adds a direct call from the ufshcd module to the ufshpb
  module which is a device handler.

Bart.