2020-07-23 11:48:56

by Can Guo

Subject: [PATCH v6 3/8] scsi: ufs-qcom: Fix schedule while atomic error in ufs_qcom_dump_dbg_regs

Dumping testbus registers needs to sleep a bit intermittently as there are
too many of them. Skip them for those contexts where sleep is not allowed.

Signed-off-by: Can Guo <[email protected]>
---
drivers/scsi/ufs/ufs-qcom.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
index 7da27ee..7831b2b 100644
--- a/drivers/scsi/ufs/ufs-qcom.c
+++ b/drivers/scsi/ufs/ufs-qcom.c
@@ -1651,13 +1651,16 @@ static void ufs_qcom_dump_dbg_regs(struct ufs_hba *hba)
ufshcd_dump_regs(hba, REG_UFS_SYS1CLK_1US, 16 * 4,
"HCI Vendor Specific Registers ");

- /* sleep a bit intermittently as we are dumping too much data */
ufs_qcom_print_hw_debug_reg_all(hba, NULL, ufs_qcom_dump_regs_wrapper);
- udelay(1000);
- ufs_qcom_testbus_read(hba);
- udelay(1000);
- ufs_qcom_print_unipro_testbus(hba);
- udelay(1000);
+
+ if (in_task()) {
+ /* sleep a bit intermittently as we are dumping too much data */
+ usleep_range(1000, 1100);
+ ufs_qcom_testbus_read(hba);
+ usleep_range(1000, 1100);
+ ufs_qcom_print_unipro_testbus(hba);
+ usleep_range(1000, 1100);
+ }
}

/**
--
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2020-07-27 13:07:06

by Avri Altman

Subject: RE: [PATCH v6 3/8] scsi: ufs-qcom: Fix schedule while atomic error in ufs_qcom_dump_dbg_regs

> Dumping testbus registers needs to sleep a bit intermittently as there are
> too many of them. Skip them for those contexts where sleep is not allowed.
>
> Signed-off-by: Can Guo <[email protected]>
> ---
> drivers/scsi/ufs/ufs-qcom.c | 15 +++++++++------
> 1 file changed, 9 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
> index 7da27ee..7831b2b 100644
> --- a/drivers/scsi/ufs/ufs-qcom.c
> +++ b/drivers/scsi/ufs/ufs-qcom.c
> @@ -1651,13 +1651,16 @@ static void ufs_qcom_dump_dbg_regs(struct
> ufs_hba *hba)
> ufshcd_dump_regs(hba, REG_UFS_SYS1CLK_1US, 16 * 4,
> "HCI Vendor Specific Registers ");
>
> - /* sleep a bit intermittently as we are dumping too much data */
> ufs_qcom_print_hw_debug_reg_all(hba, NULL,
> ufs_qcom_dump_regs_wrapper);
> - udelay(1000);
> - ufs_qcom_testbus_read(hba);
> - udelay(1000);
> - ufs_qcom_print_unipro_testbus(hba);
> - udelay(1000);
> +
> + if (in_task()) {
> + /* sleep a bit intermittently as we are dumping too much data */
> + usleep_range(1000, 1100);
> + ufs_qcom_testbus_read(hba);
> + usleep_range(1000, 1100);
> + ufs_qcom_print_unipro_testbus(hba);
> + usleep_range(1000, 1100);
> + }
> }
How about moving the intermittent sleep out of the check if preemption is disabled?
And maybe then you need to switch back to uedlay?

2020-07-28 02:22:21

by Can Guo

Subject: Re: [PATCH v6 3/8] scsi: ufs-qcom: Fix schedule while atomic error in ufs_qcom_dump_dbg_regs

Hi Avri,

On 2020-07-27 21:05, Avri Altman wrote:
>> Dumping testbus registers needs to sleep a bit intermittently as there
>> are
>> too many of them. Skip them for those contexts where sleep is not
>> allowed.
>>
>> Signed-off-by: Can Guo <[email protected]>
>> ---
>> drivers/scsi/ufs/ufs-qcom.c | 15 +++++++++------
>> 1 file changed, 9 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
>> index 7da27ee..7831b2b 100644
>> --- a/drivers/scsi/ufs/ufs-qcom.c
>> +++ b/drivers/scsi/ufs/ufs-qcom.c
>> @@ -1651,13 +1651,16 @@ static void ufs_qcom_dump_dbg_regs(struct
>> ufs_hba *hba)
>> ufshcd_dump_regs(hba, REG_UFS_SYS1CLK_1US, 16 * 4,
>> "HCI Vendor Specific Registers ");
>>
>> - /* sleep a bit intermittently as we are dumping too much data
>> */
>> ufs_qcom_print_hw_debug_reg_all(hba, NULL,
>> ufs_qcom_dump_regs_wrapper);
>> - udelay(1000);
>> - ufs_qcom_testbus_read(hba);
>> - udelay(1000);
>> - ufs_qcom_print_unipro_testbus(hba);
>> - udelay(1000);
>> +
>> + if (in_task()) {
>> + /* sleep a bit intermittently as we are dumping too
>> much data */
>> + usleep_range(1000, 1100);
>> + ufs_qcom_testbus_read(hba);
>> + usleep_range(1000, 1100);
>> + ufs_qcom_print_unipro_testbus(hba);
>> + usleep_range(1000, 1100);
>> + }
>> }
> How about moving the intermittent sleep out of the check if preemption
> is disabled?
> And maybe then you need to switch back to uedlay?

I will just remove all the testbus prints in next version to save us
time here.

Thanks,

Can Guo.