Re: [RESEND] [PATCH v11 2/6] added UFS 2.0 capabilities

Joao Pinto
2016-03-29T11:53:47Z

On 3/29/2016 12:33 PM, Winkler, Tomas wrote:
> Hi Thomas,
>
> On 3/29/2016 11:41 AM, Winkler, Tomas wrote:
>>
>> Adding UFS 2.0 support to the UFS core driver.
>>
>> Signed-off-by: Joao Pinto <jpinto@synopsys.com>
>> Acked-by: Arnd Bergmann <arnd@arndb.de>
>> Acked-by: Rob Herring <robh@kernel.org>
>> ---
>> Changes v8->v11:
>> - Nothing changed (just to keep up with patch set version).
>> Changes v7->v8:
>> - Added "jedec, ufs-2.0" to the ufschd-platform compatibility strings Changes v0->v7:
>> - Nothing changed (just to keep up with patch set version).
>>
>> .../devicetree/bindings/ufs/ufshcd-pltfrm.txt | 4 +--
>> drivers/scsi/ufs/ufshcd.c | 29 +++++++++++++++++++---
>> drivers/scsi/ufs/ufshci.h | 1 +
>> 3 files changed, 28 insertions(+), 6 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt
>> b/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt
>> index 03c0e98..8d9a9d2 100644
>> --- a/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt
>> +++ b/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt
>> @@ -4,8 +4,8 @@ UFSHC nodes are defined to describe on-chip UFS host controllers.
>> Each UFS controller instance should have its own node.
>>
>> Required properties:
>> -- compatible : must contain "jedec,ufs-1.1", may also list one or more
>> - of the following:
>> +- compatible : must contain "jedec,ufs-1.1" or "jedec,ufs-2.0", may
>> + also list one or more of the following:
>> "qcom,msm8994-ufshc"
>> "qcom,msm8996-ufshc"
>> "qcom,ufshc"
>> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
>> index 85cd256..2b5f2bf 100644
>>
>> I think this should go in separate patch
>
> In my opinion it only makes sense to add 2.0 to the device-tree binding if the driver actually supports it, that was why I added to the same patch, but of course it can be separated if more people agree with the approach.
>
> Yes, we have ufshcd-pci device that needs that so I think this should go separately

I will separate this, no problem.

>>
>> --- a/drivers/scsi/ufs/ufshcd.c
>> +++ b/drivers/scsi/ufs/ufshcd.c
>> @@ -1223,6 +1223,7 @@ static int ufshcd_compose_upiu(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
>> ret = -EINVAL;
>> }
>> break;
>> + case UTP_CMD_TYPE_UFS_STORAGE:
>> case UTP_CMD_TYPE_DEV_MANAGE:
>> ufshcd_prepare_req_desc_hdr(lrbp, &upiu_flags, DMA_NONE);
>> if (hba->dev_cmd.type == DEV_CMD_TYPE_QUERY) @@ -1287,6 +1288,7 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
>> struct ufshcd_lrb *lrbp;
>> struct ufs_hba *hba;
>> unsigned long flags;
>> + u32 upiu_flags;
>> int tag;
>> int err = 0;
>>
>> @@ -1343,10 +1345,23 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
>> lrbp->task_tag = tag;
>> lrbp->lun = ufshcd_scsi_to_upiu_lun(cmd->device->lun);
>> lrbp->intr_cmd = !ufshcd_is_intr_aggr_allowed(hba) ? true : false;
>> - lrbp->command_type = UTP_CMD_TYPE_SCSI;
>> +
>> + if (hba->ufs_version == UFSHCI_VERSION_20)
>> + lrbp->command_type = UTP_CMD_TYPE_UFS_STORAGE;
>> + else
>> + lrbp->command_type = UTP_CMD_TYPE_SCSI;
>> This translation can be pushed to prepare_req_desc_hdr and you end up
>> with ~oneliner fix
>
> I think your suggestion is good! We have to check the 2.0 version in 2 places and with your approach we would only check it in prepare_req_desc_hdr() once.
> I will do that update!
>
> Okay I think you can alter ufshcd_lrb structure and push the information there,
> Add ufs version there as hba is not available in req_desc_hdr, I think both command_type and ufs_version can be u8 so the structure won't grow.

Going to check it out.

>
>
>>
>>
>> /* form UPIU before issuing the command */
>> - ufshcd_compose_upiu(hba, lrbp);
>> + if (hba->ufs_version == UFSHCI_VERSION_20) {
>> + if (likely(lrbp->cmd)) {
>> How this can be possible NULL, the code above will crash or I'm missing something ?
>> + ufshcd_prepare_req_desc_hdr(lrbp, &upiu_flags,
>> + lrbp->cmd->sc_data_direction);
>> + ufshcd_prepare_utp_scsi_cmd_upiu(lrbp, upiu_flags);
>> What is different her from the code in ufshcd_compose_upiu ?
>> + } else
>> + err = -EINVAL;
>> + } else
>> + ufshcd_compose_upiu(hba, lrbp);
>
> If you check ufshcd_compose_upiu() you will see that it contains 2 scopes:
> cmd_upiu and query_req_upiu. Before 2.0 this single function approach that had both scopes worked well, but now with 2.0 we must use the same command_type
> (UTP_CMD_TYPE_UFS_STORAGE) which causes incompatibility. This was why I put the same code from cmd_upiu in the outside.
>
> Of course we can break ufshcd_compose_upiu() in 2: ufshcd_compose_cmd_upiu() and ufshcd_compose_query_upiu(). What do you think?
> If you use ufs_version only in req_desc_hdr then you don't need this
>
> If (ufs_version == 2.0)
> cmd_type = UFS_STORAGE
> else
> cmd_type = lrb->command_type
>
> ...
> I think with this change

Ok, I will test that.

>
>> +
>> err = ufshcd_map_sg(lrbp);
>> if (err) {
>> lrbp->cmd = NULL;
>> @@ -1371,7 +1386,12 @@ static int ufshcd_compose_dev_cmd(struct ufs_hba *hba,
>> lrbp->sense_buffer = NULL;

[snip]

>> complete(hba->dev_cmd.complete);
>> }
>> diff --git a/drivers/scsi/ufs/ufshci.h b/drivers/scsi/ufs/ufshci.h
>> index 0ae0967..8dba0e7 100644
>> --- a/drivers/scsi/ufs/ufshci.h
>> +++ b/drivers/scsi/ufs/ufshci.h
>> @@ -273,6 +273,7 @@ enum {
>> UTP_CMD_TYPE_SCSI = 0x0,
>> UTP_CMD_TYPE_UFS = 0x1,
>> UTP_CMD_TYPE_DEV_MANAGE = 0x2,
>> + UTP_CMD_TYPE_UFS_STORAGE = 0x11,
> Why 0x11?

I'll have to check with our R&D team.

>
> Thanks
> Tomas
>

Thanks
Joao