Re: [PATCH 1/4] scsi: ufs: add quirk to fix mishandling utrlclr/utmrlclr

From: Subhash Jadavani
Date: Wed May 16 2018 - 16:51:16 EST


On 2018-05-06 03:14, Alim Akhtar wrote:
In the right behavior, setting the bit to '0' indicates clear and
'1' indicates no change. If host controller handles this the other way,
UFSHCI_QUIRK_BROKEN_REQ_LIST_CLR can be used.

Signed-off-by: Seungwon Jeon <essuuj@xxxxxxxxx>
Signed-off-by: Alim Akhtar <alim.akhtar@xxxxxxxxxxx>
---
drivers/scsi/ufs/ufshcd.c | 21 +++++++++++++++++++--
drivers/scsi/ufs/ufshcd.h | 5 +++++
2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 00e7905..9898ce5 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -675,7 +675,24 @@ static inline void ufshcd_put_tm_slot(struct
ufs_hba *hba, int slot)
*/
static inline void ufshcd_utrl_clear(struct ufs_hba *hba, u32 pos)
{
- ufshcd_writel(hba, ~(1 << pos), REG_UTP_TRANSFER_REQ_LIST_CLEAR);
+ if (hba->quirks & UFSHCI_QUIRK_BROKEN_REQ_LIST_CLR)
+ ufshcd_writel(hba, (1 << pos), REG_UTP_TRANSFER_REQ_LIST_CLEAR);
+ else
+ ufshcd_writel(hba, ~(1 << pos),
+ REG_UTP_TRANSFER_REQ_LIST_CLEAR);
+}
+
+/**
+ * ufshcd_utmrl_clear - Clear a bit in UTRMLCLR register
+ * @hba: per adapter instance
+ * @pos: position of the bit to be cleared
+ */
+static inline void ufshcd_utmrl_clear(struct ufs_hba *hba, u32 pos)
+{
+ if (hba->quirks & UFSHCI_QUIRK_BROKEN_REQ_LIST_CLR)
+ ufshcd_writel(hba, (1 << pos), REG_UTP_TASK_REQ_LIST_CLEAR);
+ else
+ ufshcd_writel(hba, ~(1 << pos), REG_UTP_TASK_REQ_LIST_CLEAR);
}

/**
@@ -5398,7 +5415,7 @@ static int ufshcd_clear_tm_cmd(struct ufs_hba
*hba, int tag)
goto out;

spin_lock_irqsave(hba->host->host_lock, flags);
- ufshcd_writel(hba, ~(1 << tag), REG_UTP_TASK_REQ_LIST_CLEAR);
+ ufshcd_utmrl_clear(hba, tag);
spin_unlock_irqrestore(hba->host->host_lock, flags);

/* poll for max. 1 sec to clear door bell register by h/w */
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 8110dcd..43035f8 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -595,6 +595,11 @@ struct ufs_hba {
*/
#define UFSHCD_QUIRK_PRDT_BYTE_GRAN 0x80

+ /*
+ * Cleaer handling for transfer/task request list is just opposite.
+ */
+ #define UFSHCI_QUIRK_BROKEN_REQ_LIST_CLR 0x100
+
unsigned int quirks; /* Deviations from standard UFSHCI spec. */

/* Device deviations from standard UFS device spec. */

Looks good to me.
Reviewed-by: Subhash Jadavani <subhashj@xxxxxxxxxxxxxx>

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