RE: Re: [PATCH v35 3/4] scsi: ufs: Prepare HPB read for cached sub-region

[Daejun Park <daejun7.park@samsung.com>]

Hi Bart,

>> +static void
>> +ufshpb_set_hpb_read_to_upiu(struct ufshpb_lu *hpb, struct ufshcd_lrb *lrbp,
>> +                            u32 lpn, u64 ppn, u8 transfer_len)
>> +{
>> +        unsigned char *cdb = lrbp->cmd->cmnd;
>> +
>> +        cdb[0] = UFSHPB_READ;
>> +
>> +        /* ppn value is stored as big-endian in the host memory */
> 
>I think that that comment means that the type of the 'ppn' argument
>should be changed from 'u64' into __be64.

OK, I will change it.

> 
>> +        memcpy(&cdb[6], &ppn, sizeof(__be64));
>> +        cdb[14] = transfer_len;
>> +
>> +        lrbp->cmd->cmd_len = UFS_CDB_SIZE;
>> +}
>> +
>> +/*
>> + * This function will set up HPB read command using host-side L2P map data.
>> + * In HPB v1.0, maximum size of HPB read command is 4KB.
>> + */
>> +void ufshpb_prep(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
>> +{
>[ ... ]
>> +
>> +        ufshpb_set_hpb_read_to_upiu(hpb, lrbp, lpn, ppn, transfer_len);
> 
>'transfer_len' has type int and is truncated to type 'u8' when passed as
>an argument to ufshpb_set_hpb_read_to_upiu(). Please handle transfer_len
>values >= 256 properly.

Before entering the function, ufshpb_is_supported_chunk() checks whether
transfer_len <= hpb->pre_req_max_tr_len which is set to
HPB_MULTI_CHUNK_HIGH (128) on initalization.

Thanks,
Daejun