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

Joao Pinto
2016-03-29T11:08:15Z

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.

>
> --- 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!

>
>
> /* 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?

> +
> 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;
> lrbp->task_tag = tag;
> lrbp->lun = 0; /* device management cmd is not specific to any LUN */
> - lrbp->command_type = UTP_CMD_TYPE_DEV_MANAGE;
> +
> + if (hba->ufs_version == UFSHCI_VERSION_20)
> + lrbp->command_type = UTP_CMD_TYPE_UFS_STORAGE;
> + else
> + lrbp->command_type = UTP_CMD_TYPE_DEV_MANAGE;
> +
> This translation can be pushed to prepare_req_desc_hdr and you end up with ~ oneliner fix
>
> lrbp->intr_cmd = true; /* No interrupt aggregation */
> hba->dev_cmd.type = cmd_type;
>
> @@ -3187,7 +3207,8 @@ static void ufshcd_transfer_req_compl(struct ufs_hba *hba)
> /* Do not touch lrbp after scsi done */
> cmd->scsi_done(cmd);
> __ufshcd_release(hba);
> - } else if (lrbp->command_type == UTP_CMD_TYPE_DEV_MANAGE) {
> + } else if (lrbp->command_type == UTP_CMD_TYPE_DEV_MANAGE ||
> + lrbp->command_type == UTP_CMD_TYPE_UFS_STORAGE) {
> if (hba->dev_cmd.complete)
> 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,
> };
>
> enum {
> --
> 1.8.1.5
>
> --
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>

Thanks,
Joao