In interrupt context, after reading and comparing the UTRLDBR to
hba->outstanding_request and before resetting the interrupt aggregation,
there might be completion of another transfer request (TR). Such TRs might
get stuck, pending, until the next interrupt is generated.
The fix reads the UTRLDBR after resetting the interrupt aggregation and
handles completed TRs.
Signed-off-by: Dolev Raviv <[email protected]>
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 4dca9b4..30c84d8 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -1915,6 +1915,13 @@ static void ufshcd_uic_cmd_compl(struct ufs_hba *hba)
/**
* ufshcd_transfer_req_compl - handle SCSI and query command completion
* @hba: per adapter instance
+ *
+ * Resetting interrupt aggregation counters first and reading the DOOR_BELL
+ * afterward , allows us to handle all the completed requests.
+ * In order to prevent other interrupts starvation the DB is read once
+ * after reset. The down side of this solution is the possibility of false
+ * interrupt if device completes another request after resetting aggregation
+ * and before reading the DB.
*/
static void ufshcd_transfer_req_compl(struct ufs_hba *hba)
{
@@ -1924,47 +1931,36 @@ static void ufshcd_transfer_req_compl(struct ufs_hba *hba)
u32 tr_doorbell;
int result;
int index;
- bool int_aggr_reset = false;
+
+ /* Reset interrupt aggregation counters */
+ ufshcd_config_int_aggr(hba, INT_AGGR_RESET);
tr_doorbell = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL);
completed_reqs = tr_doorbell ^ hba->outstanding_reqs;
- for (index = 0; index < hba->nutrs; index++) {
- if (test_bit(index, &completed_reqs)) {
- lrbp = &hba->lrb[index];
- cmd = lrbp->cmd;
- /*
- * Don't skip resetting interrupt aggregation counters
- * if a regular command is present.
- */
- int_aggr_reset |= !lrbp->intr_cmd;
-
- if (cmd) {
- result = ufshcd_transfer_rsp_status(hba, lrbp);
- scsi_dma_unmap(cmd);
- cmd->result = result;
- /* Mark completed command as NULL in LRB */
- lrbp->cmd = NULL;
- clear_bit_unlock(index, &hba->lrb_in_use);
- /* Do not touch lrbp after scsi done */
- cmd->scsi_done(cmd);
- } else if (lrbp->command_type ==
- UTP_CMD_TYPE_DEV_MANAGE) {
- if (hba->dev_cmd.complete)
- complete(hba->dev_cmd.complete);
- }
- } /* end of if */
- } /* end of for */
+ for_each_set_bit(index, &completed_reqs, hba->nutrs) {
+ lrbp = &hba->lrb[index];
+ cmd = lrbp->cmd;
+ if (cmd) {
+ result = ufshcd_transfer_rsp_status(hba, lrbp);
+ scsi_dma_unmap(cmd);
+ cmd->result = result;
+ /* Mark completed command as NULL in LRB */
+ lrbp->cmd = NULL;
+ clear_bit_unlock(index, &hba->lrb_in_use);
+ /* Do not touch lrbp after scsi done */
+ cmd->scsi_done(cmd);
+ } else if (lrbp->command_type == UTP_CMD_TYPE_DEV_MANAGE) {
+ if (hba->dev_cmd.complete)
+ complete(hba->dev_cmd.complete);
+ }
+ } /* end of for_each_set_bit */
/* clear corresponding bits of completed commands */
hba->outstanding_reqs ^= completed_reqs;
/* we might have free'd some tags above */
wake_up(&hba->dev_cmd.tag_wq);
-
- /* Reset interrupt aggregation counters */
- if (int_aggr_reset)
- ufshcd_config_int_aggr(hba, INT_AGGR_RESET);
}
/**
@@ -2569,6 +2565,7 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)
int poll_cnt;
u8 resp = 0xF;
struct ufshcd_lrb *lrbp;
+ u32 reg;
host = cmd->device->host;
hba = shost_priv(host);
@@ -2578,6 +2575,13 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)
if (!(test_bit(tag, &hba->outstanding_reqs)))
goto out;
+ reg = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL);
+ if (!(reg & (1 << tag))) {
+ dev_err(hba->dev,
+ "%s: cmd was completed, but without a notifying intr, tag = %d",
+ __func__, tag);
+ }
+
lrbp = &hba->lrb[tag];
for (poll_cnt = 100; poll_cnt; poll_cnt--) {
err = ufshcd_issue_tm_cmd(hba, lrbp->lun, lrbp->task_tag,
@@ -2586,8 +2590,6 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)
/* cmd pending in the device */
break;
} else if (!err && resp == UPIU_TASK_MANAGEMENT_FUNC_COMPL) {
- u32 reg;
-
/*
* cmd not pending in the device, check if it is
* in transition.
--
1.7.6
--
QUALCOMM ISRAEL, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation
Looks good to me.
Reviewed-by: Subhash Jadavani <[email protected]>
On 8/25/2013 4:06 PM, Dolev Raviv wrote:
> In interrupt context, after reading and comparing the UTRLDBR to
> hba->outstanding_request and before resetting the interrupt aggregation,
> there might be completion of another transfer request (TR). Such TRs might
> get stuck, pending, until the next interrupt is generated.
>
> The fix reads the UTRLDBR after resetting the interrupt aggregation and
> handles completed TRs.
>
> Signed-off-by: Dolev Raviv <[email protected]>
>
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 4dca9b4..30c84d8 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -1915,6 +1915,13 @@ static void ufshcd_uic_cmd_compl(struct ufs_hba *hba)
> /**
> * ufshcd_transfer_req_compl - handle SCSI and query command completion
> * @hba: per adapter instance
> + *
> + * Resetting interrupt aggregation counters first and reading the DOOR_BELL
> + * afterward , allows us to handle all the completed requests.
> + * In order to prevent other interrupts starvation the DB is read once
> + * after reset. The down side of this solution is the possibility of false
> + * interrupt if device completes another request after resetting aggregation
> + * and before reading the DB.
> */
> static void ufshcd_transfer_req_compl(struct ufs_hba *hba)
> {
> @@ -1924,47 +1931,36 @@ static void ufshcd_transfer_req_compl(struct ufs_hba *hba)
> u32 tr_doorbell;
> int result;
> int index;
> - bool int_aggr_reset = false;
> +
> + /* Reset interrupt aggregation counters */
> + ufshcd_config_int_aggr(hba, INT_AGGR_RESET);
>
> tr_doorbell = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL);
> completed_reqs = tr_doorbell ^ hba->outstanding_reqs;
>
> - for (index = 0; index < hba->nutrs; index++) {
> - if (test_bit(index, &completed_reqs)) {
> - lrbp = &hba->lrb[index];
> - cmd = lrbp->cmd;
> - /*
> - * Don't skip resetting interrupt aggregation counters
> - * if a regular command is present.
> - */
> - int_aggr_reset |= !lrbp->intr_cmd;
> -
> - if (cmd) {
> - result = ufshcd_transfer_rsp_status(hba, lrbp);
> - scsi_dma_unmap(cmd);
> - cmd->result = result;
> - /* Mark completed command as NULL in LRB */
> - lrbp->cmd = NULL;
> - clear_bit_unlock(index, &hba->lrb_in_use);
> - /* Do not touch lrbp after scsi done */
> - cmd->scsi_done(cmd);
> - } else if (lrbp->command_type ==
> - UTP_CMD_TYPE_DEV_MANAGE) {
> - if (hba->dev_cmd.complete)
> - complete(hba->dev_cmd.complete);
> - }
> - } /* end of if */
> - } /* end of for */
> + for_each_set_bit(index, &completed_reqs, hba->nutrs) {
> + lrbp = &hba->lrb[index];
> + cmd = lrbp->cmd;
> + if (cmd) {
> + result = ufshcd_transfer_rsp_status(hba, lrbp);
> + scsi_dma_unmap(cmd);
> + cmd->result = result;
> + /* Mark completed command as NULL in LRB */
> + lrbp->cmd = NULL;
> + clear_bit_unlock(index, &hba->lrb_in_use);
> + /* Do not touch lrbp after scsi done */
> + cmd->scsi_done(cmd);
> + } else if (lrbp->command_type == UTP_CMD_TYPE_DEV_MANAGE) {
> + if (hba->dev_cmd.complete)
> + complete(hba->dev_cmd.complete);
> + }
> + } /* end of for_each_set_bit */
>
> /* clear corresponding bits of completed commands */
> hba->outstanding_reqs ^= completed_reqs;
>
> /* we might have free'd some tags above */
> wake_up(&hba->dev_cmd.tag_wq);
> -
> - /* Reset interrupt aggregation counters */
> - if (int_aggr_reset)
> - ufshcd_config_int_aggr(hba, INT_AGGR_RESET);
> }
>
> /**
> @@ -2569,6 +2565,7 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)
> int poll_cnt;
> u8 resp = 0xF;
> struct ufshcd_lrb *lrbp;
> + u32 reg;
>
> host = cmd->device->host;
> hba = shost_priv(host);
> @@ -2578,6 +2575,13 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)
> if (!(test_bit(tag, &hba->outstanding_reqs)))
> goto out;
>
> + reg = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL);
> + if (!(reg & (1 << tag))) {
> + dev_err(hba->dev,
> + "%s: cmd was completed, but without a notifying intr, tag = %d",
> + __func__, tag);
> + }
> +
> lrbp = &hba->lrb[tag];
> for (poll_cnt = 100; poll_cnt; poll_cnt--) {
> err = ufshcd_issue_tm_cmd(hba, lrbp->lun, lrbp->task_tag,
> @@ -2586,8 +2590,6 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)
> /* cmd pending in the device */
> break;
> } else if (!err && resp == UPIU_TASK_MANAGEMENT_FUNC_COMPL) {
> - u32 reg;
> -
> /*
> * cmd not pending in the device, check if it is
> * in transition.
On 8/27/2013 1:50 PM, Subhash Jadavani wrote:
>
>
> Looks good to me.
> Reviewed-by: Subhash Jadavani <[email protected]>
>
> On 8/25/2013 4:06 PM, Dolev Raviv wrote:
>> In interrupt context, after reading and comparing the UTRLDBR to
>> hba->outstanding_request and before resetting the interrupt aggregation,
>> there might be completion of another transfer request (TR). Such TRs
>> might
>> get stuck, pending, until the next interrupt is generated.
>>
>> The fix reads the UTRLDBR after resetting the interrupt aggregation and
>> handles completed TRs.
>>
>> Signed-off-by: Dolev Raviv <[email protected]>
>>
>> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
>> index 4dca9b4..30c84d8 100644
>> --- a/drivers/scsi/ufs/ufshcd.c
>> +++ b/drivers/scsi/ufs/ufshcd.c
>> @@ -1915,6 +1915,13 @@ static void ufshcd_uic_cmd_compl(struct
>> ufs_hba *hba)
>> /**
>> * ufshcd_transfer_req_compl - handle SCSI and query command
>> completion
>> * @hba: per adapter instance
>> + *
>> + * Resetting interrupt aggregation counters first and reading the
>> DOOR_BELL
>> + * afterward , allows us to handle all the completed requests.
>> + * In order to prevent other interrupts starvation the DB is read once
>> + * after reset. The down side of this solution is the possibility of
>> false
>> + * interrupt if device completes another request after resetting
>> aggregation
>> + * and before reading the DB.
>> */
>> static void ufshcd_transfer_req_compl(struct ufs_hba *hba)
>> {
>> @@ -1924,47 +1931,36 @@ static void ufshcd_transfer_req_compl(struct
>> ufs_hba *hba)
>> u32 tr_doorbell;
>> int result;
>> int index;
>> - bool int_aggr_reset = false;
>> +
>> + /* Reset interrupt aggregation counters */
>> + ufshcd_config_int_aggr(hba, INT_AGGR_RESET);
You may have to rebase your change on top of "[PATCH v3 2/6] scsi: ufs:
fix the setting interrupt aggregation counter" patch. Once you do that,
you will be calling ufshcd_reset_intr_aggr() (instead of
ufshscd_config_int_aggr()) to reset the interrupt aggregation counters.
>> tr_doorbell = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL);
>> completed_reqs = tr_doorbell ^ hba->outstanding_reqs;
>> - for (index = 0; index < hba->nutrs; index++) {
>> - if (test_bit(index, &completed_reqs)) {
>> - lrbp = &hba->lrb[index];
>> - cmd = lrbp->cmd;
>> - /*
>> - * Don't skip resetting interrupt aggregation counters
>> - * if a regular command is present.
>> - */
>> - int_aggr_reset |= !lrbp->intr_cmd;
>> -
>> - if (cmd) {
>> - result = ufshcd_transfer_rsp_status(hba, lrbp);
>> - scsi_dma_unmap(cmd);
>> - cmd->result = result;
>> - /* Mark completed command as NULL in LRB */
>> - lrbp->cmd = NULL;
>> - clear_bit_unlock(index, &hba->lrb_in_use);
>> - /* Do not touch lrbp after scsi done */
>> - cmd->scsi_done(cmd);
>> - } else if (lrbp->command_type ==
>> - UTP_CMD_TYPE_DEV_MANAGE) {
>> - if (hba->dev_cmd.complete)
>> - complete(hba->dev_cmd.complete);
>> - }
>> - } /* end of if */
>> - } /* end of for */
>> + for_each_set_bit(index, &completed_reqs, hba->nutrs) {
>> + lrbp = &hba->lrb[index];
>> + cmd = lrbp->cmd;
>> + if (cmd) {
>> + result = ufshcd_transfer_rsp_status(hba, lrbp);
>> + scsi_dma_unmap(cmd);
>> + cmd->result = result;
>> + /* Mark completed command as NULL in LRB */
>> + lrbp->cmd = NULL;
>> + clear_bit_unlock(index, &hba->lrb_in_use);
>> + /* Do not touch lrbp after scsi done */
>> + cmd->scsi_done(cmd);
>> + } else if (lrbp->command_type == UTP_CMD_TYPE_DEV_MANAGE) {
>> + if (hba->dev_cmd.complete)
>> + complete(hba->dev_cmd.complete);
>> + }
>> + } /* end of for_each_set_bit */
>> /* clear corresponding bits of completed commands */
>> hba->outstanding_reqs ^= completed_reqs;
>> /* we might have free'd some tags above */
>> wake_up(&hba->dev_cmd.tag_wq);
>> -
>> - /* Reset interrupt aggregation counters */
>> - if (int_aggr_reset)
>> - ufshcd_config_int_aggr(hba, INT_AGGR_RESET);
>> }
>> /**
>> @@ -2569,6 +2565,7 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)
>> int poll_cnt;
>> u8 resp = 0xF;
>> struct ufshcd_lrb *lrbp;
>> + u32 reg;
>> host = cmd->device->host;
>> hba = shost_priv(host);
>> @@ -2578,6 +2575,13 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)
>> if (!(test_bit(tag, &hba->outstanding_reqs)))
>> goto out;
>> + reg = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL);
>> + if (!(reg & (1 << tag))) {
>> + dev_err(hba->dev,
>> + "%s: cmd was completed, but without a notifying intr, tag =
>> %d",
>> + __func__, tag);
>> + }
>> +
>> lrbp = &hba->lrb[tag];
>> for (poll_cnt = 100; poll_cnt; poll_cnt--) {
>> err = ufshcd_issue_tm_cmd(hba, lrbp->lun, lrbp->task_tag,
>> @@ -2586,8 +2590,6 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)
>> /* cmd pending in the device */
>> break;
>> } else if (!err && resp == UPIU_TASK_MANAGEMENT_FUNC_COMPL) {
>> - u32 reg;
>> -
>> /*
>> * cmd not pending in the device, check if it is
>> * in transition.
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
Tested-by: Yaniv Gardi <[email protected]>
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Subhash Jadavani
Sent: Tuesday, August 27, 2013 11:59 AM
To: Dolev Raviv
Cc: [email protected]; [email protected]; open list
Subject: Re: [PATCH] scsi: ufs: read door bell register after clearing
interrupt aggregation
On 8/27/2013 1:50 PM, Subhash Jadavani wrote:
>
>
> Looks good to me.
> Reviewed-by: Subhash Jadavani <[email protected]>
>
> On 8/25/2013 4:06 PM, Dolev Raviv wrote:
>> In interrupt context, after reading and comparing the UTRLDBR to
>> hba->outstanding_request and before resetting the interrupt
>> hba->aggregation,
>> there might be completion of another transfer request (TR). Such TRs
>> might get stuck, pending, until the next interrupt is generated.
>>
>> The fix reads the UTRLDBR after resetting the interrupt aggregation
>> and handles completed TRs.
>>
>> Signed-off-by: Dolev Raviv <[email protected]>
>>
>> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
>> index 4dca9b4..30c84d8 100644
>> --- a/drivers/scsi/ufs/ufshcd.c
>> +++ b/drivers/scsi/ufs/ufshcd.c
>> @@ -1915,6 +1915,13 @@ static void ufshcd_uic_cmd_compl(struct
>> ufs_hba *hba)
>> /**
>> * ufshcd_transfer_req_compl - handle SCSI and query command
>> completion
>> * @hba: per adapter instance
>> + *
>> + * Resetting interrupt aggregation counters first and reading the
>> DOOR_BELL
>> + * afterward , allows us to handle all the completed requests.
>> + * In order to prevent other interrupts starvation the DB is read
>> + once
>> + * after reset. The down side of this solution is the possibility of
>> false
>> + * interrupt if device completes another request after resetting
>> aggregation
>> + * and before reading the DB.
>> */
>> static void ufshcd_transfer_req_compl(struct ufs_hba *hba)
>> {
>> @@ -1924,47 +1931,36 @@ static void ufshcd_transfer_req_compl(struct
>> ufs_hba *hba)
>> u32 tr_doorbell;
>> int result;
>> int index;
>> - bool int_aggr_reset = false;
>> +
>> + /* Reset interrupt aggregation counters */
>> + ufshcd_config_int_aggr(hba, INT_AGGR_RESET);
You may have to rebase your change on top of "[PATCH v3 2/6] scsi: ufs:
fix the setting interrupt aggregation counter" patch. Once you do that, you
will be calling ufshcd_reset_intr_aggr() (instead of
ufshscd_config_int_aggr()) to reset the interrupt aggregation counters.
>> tr_doorbell = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL);
>> completed_reqs = tr_doorbell ^ hba->outstanding_reqs;
>> - for (index = 0; index < hba->nutrs; index++) {
>> - if (test_bit(index, &completed_reqs)) {
>> - lrbp = &hba->lrb[index];
>> - cmd = lrbp->cmd;
>> - /*
>> - * Don't skip resetting interrupt aggregation counters
>> - * if a regular command is present.
>> - */
>> - int_aggr_reset |= !lrbp->intr_cmd;
>> -
>> - if (cmd) {
>> - result = ufshcd_transfer_rsp_status(hba, lrbp);
>> - scsi_dma_unmap(cmd);
>> - cmd->result = result;
>> - /* Mark completed command as NULL in LRB */
>> - lrbp->cmd = NULL;
>> - clear_bit_unlock(index, &hba->lrb_in_use);
>> - /* Do not touch lrbp after scsi done */
>> - cmd->scsi_done(cmd);
>> - } else if (lrbp->command_type ==
>> - UTP_CMD_TYPE_DEV_MANAGE) {
>> - if (hba->dev_cmd.complete)
>> - complete(hba->dev_cmd.complete);
>> - }
>> - } /* end of if */
>> - } /* end of for */
>> + for_each_set_bit(index, &completed_reqs, hba->nutrs) {
>> + lrbp = &hba->lrb[index];
>> + cmd = lrbp->cmd;
>> + if (cmd) {
>> + result = ufshcd_transfer_rsp_status(hba, lrbp);
>> + scsi_dma_unmap(cmd);
>> + cmd->result = result;
>> + /* Mark completed command as NULL in LRB */
>> + lrbp->cmd = NULL;
>> + clear_bit_unlock(index, &hba->lrb_in_use);
>> + /* Do not touch lrbp after scsi done */
>> + cmd->scsi_done(cmd);
>> + } else if (lrbp->command_type == UTP_CMD_TYPE_DEV_MANAGE) {
>> + if (hba->dev_cmd.complete)
>> + complete(hba->dev_cmd.complete);
>> + }
>> + } /* end of for_each_set_bit */
>> /* clear corresponding bits of completed commands */
>> hba->outstanding_reqs ^= completed_reqs;
>> /* we might have free'd some tags above */
>> wake_up(&hba->dev_cmd.tag_wq);
>> -
>> - /* Reset interrupt aggregation counters */
>> - if (int_aggr_reset)
>> - ufshcd_config_int_aggr(hba, INT_AGGR_RESET);
>> }
>> /**
>> @@ -2569,6 +2565,7 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)
>> int poll_cnt;
>> u8 resp = 0xF;
>> struct ufshcd_lrb *lrbp;
>> + u32 reg;
>> host = cmd->device->host;
>> hba = shost_priv(host);
>> @@ -2578,6 +2575,13 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)
>> if (!(test_bit(tag, &hba->outstanding_reqs)))
>> goto out;
>> + reg = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL);
>> + if (!(reg & (1 << tag))) {
>> + dev_err(hba->dev,
>> + "%s: cmd was completed, but without a notifying intr, tag =
>> %d",
>> + __func__, tag);
>> + }
>> +
>> lrbp = &hba->lrb[tag];
>> for (poll_cnt = 100; poll_cnt; poll_cnt--) {
>> err = ufshcd_issue_tm_cmd(hba, lrbp->lun, lrbp->task_tag,
>> @@ -2586,8 +2590,6 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)
>> /* cmd pending in the device */
>> break;
>> } else if (!err && resp == UPIU_TASK_MANAGEMENT_FUNC_COMPL) {
>> - u32 reg;
>> -
>> /*
>> * cmd not pending in the device, check if it is
>> * in transition.
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-scsi"
> in the body of a message to [email protected] More majordomo
> info at http://vger.kernel.org/majordomo-info.html