Re: [PATCH 02/10] scsi: ufs: add quirk to contain unconformable utrd field

[Alim Akhtar <alim.akhtar@samsung.com>]

Hi Amit,
Thanks for your review comments.

On 08/26/2015 11:43 AM, amit daniel kachhap wrote:
> Few minor comments below,
>
> On Fri, Aug 21, 2015 at 2:57 PM, Alim Akhtar <alim.akhtar@samsung.com> wrote:
>> From: Seungwon Jeon <tgih.jun@samsung.com>
>>
>> UTRD(UTP Transfer Request Descriptor)'s field such as offset/length,
>> especially response's has DWORD expression. This quirk can be specified
>> for host controller not to conform standard.
>>
>> Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
>> Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
>> ---
>>   drivers/scsi/ufs/ufshcd.c |   28 +++++++++++++++++++++-------
>>   drivers/scsi/ufs/ufshcd.h |    7 +++++++
>>   2 files changed, 28 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
>> index b0ade73..f882bf0 100644
>> --- a/drivers/scsi/ufs/ufshcd.c
>> +++ b/drivers/scsi/ufs/ufshcd.c
>> @@ -1009,7 +1009,7 @@ ufshcd_send_uic_cmd(struct ufs_hba *hba, struct uic_command *uic_cmd)
>>    *
>>    * Returns 0 in case of success, non-zero value in case of failure
>>    */
>> -static int ufshcd_map_sg(struct ufshcd_lrb *lrbp)
>> +static int ufshcd_map_sg(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
>>   {
>>          struct ufshcd_sg_entry *prd_table;
>>          struct scatterlist *sg;
>> @@ -1023,8 +1023,13 @@ static int ufshcd_map_sg(struct ufshcd_lrb *lrbp)
>>                  return sg_segments;
>>
>>          if (sg_segments) {
>> -               lrbp->utr_descriptor_ptr->prd_table_length =
>> -                                       cpu_to_le16((u16) (sg_segments));
>> +               if (hba->quirks & UFSHCI_QUIRK_BROKEN_UTRD)
>> +                       lrbp->utr_descriptor_ptr->prd_table_length =
>> +                               cpu_to_le16((u16)(sg_segments *
>> +                                       sizeof(struct ufshcd_sg_entry)));
>> +               else
>> +                       lrbp->utr_descriptor_ptr->prd_table_length =
>> +                               cpu_to_le16((u16) (sg_segments));
>>
>>                  prd_table = (struct ufshcd_sg_entry *)lrbp->ucd_prdt_ptr;
>>
>> @@ -1347,7 +1352,7 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
>>
>>          /* form UPIU before issuing the command */
>>          ufshcd_compose_upiu(hba, lrbp);
>> -       err = ufshcd_map_sg(lrbp);
>> +       err = ufshcd_map_sg(hba, lrbp);
>>          if (err) {
>>                  lrbp->cmd = NULL;
>>                  clear_bit_unlock(tag, &hba->lrb_in_use);
>> @@ -2035,12 +2040,21 @@ static void ufshcd_host_memory_configure(struct ufs_hba *hba)
>>                                  cpu_to_le32(upper_32_bits(cmd_desc_element_addr));
>>
>>                  /* Response upiu and prdt offset should be in double words */
> This comment can be moved below for the else case.
ok
>> -               utrdlp[i].response_upiu_offset =
>> +               if (hba->quirks & UFSHCI_QUIRK_BROKEN_UTRD) {
>> +                       utrdlp[i].response_upiu_offset =
>> +                               cpu_to_le16(response_offset);
>> +                       utrdlp[i].prd_table_offset =
>> +                               cpu_to_le16(prdt_offset);
>> +                       utrdlp[i].response_upiu_length =
>> +                               cpu_to_le16(ALIGNED_UPIU_SIZE);
>> +               } else {
>> +                       utrdlp[i].response_upiu_offset =
>>                                  cpu_to_le16((response_offset >> 2));
>> -               utrdlp[i].prd_table_offset =
>> +                       utrdlp[i].prd_table_offset =
>>                                  cpu_to_le16((prdt_offset >> 2));
>> -               utrdlp[i].response_upiu_length =
>> +                       utrdlp[i].response_upiu_length =
>>                                  cpu_to_le16(ALIGNED_UPIU_SIZE >> 2);
>> +               }
>>
>>                  hba->lrb[i].utr_descriptor_ptr = (utrdlp + i);
>>                  hba->lrb[i].ucd_req_ptr =
>> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
>> index c40a0e7..1fa5ac1 100644
>> --- a/drivers/scsi/ufs/ufshcd.h
>> +++ b/drivers/scsi/ufs/ufshcd.h
>> @@ -459,6 +459,13 @@ struct ufs_hba {
>>           */
>>          #define UFSHCD_QUIRK_BROKEN_UFS_HCI_VERSION             UFS_BIT(5)
>>
>> +       /*
>> +        * This quirk needs to be enabled if host controller doesn't conform
>> +        * with UTRD. Some fields such as offset/length might not be in double word,
>> +        * but in byte.
>> +        */
>> +       #define UFSHCI_QUIRK_BROKEN_UTRD                        UFS_BIT(6)
> This macro name may be given more meaningful name such as
> UFSHCI_QUIRK_BYTE_ALIGN_UTRD or something similar.
ok, will change
>> +
>>          unsigned int quirks;    /* Deviations from standard UFSHCI spec. */
>>
>>          wait_queue_head_t tm_wq;
>> --
>> 1.7.10.4
>>
>> --
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>