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[v2,0/3] Two changes of UFS sysfs

Message ID 20201224172010.10701-1-huobean@gmail.com
Headers show
Series Two changes of UFS sysfs | expand

Message

Bean Huo Dec. 24, 2020, 5:20 p.m. UTC
From: Bean Huo <beanhuo@micron.com>

Changelog:

V1---v2:
    1. Add new patch "Let resume callback return -EBUSY after ufshcd_shutdown",
       Because the ufshcd_*_resume still returns successful result 0 after
       ufshcd_shutdown(). Even add handling of the return value of
       pm_runtime_get_sync(), but still there is timeout.

Bean Huo (3):
  scsi: ufs: Replace sprintf and snprintf with sysfs_emit
  scsi: ufs: Add handling of the return value of pm_runtime_get_sync()
  scsi: ufs: Let resume callback return -EBUSY after ufshcd_shutdown

 drivers/scsi/ufs/ufs-sysfs.c | 68 +++++++++++++++++++++++++-----------
 drivers/scsi/ufs/ufshcd.c    | 12 ++++---
 2 files changed, 55 insertions(+), 25 deletions(-)

Comments

Can Guo Dec. 28, 2020, 1:50 a.m. UTC | #1
On 2020-12-25 01:20, Bean Huo wrote:
> From: Bean Huo <beanhuo@micron.com>

> 

> The race issue may exist between UFS access in UFS sysfs context and 

> UFS

> shutdown, thus will cause pm_runtime_get_sync() resume failure.


Are you trying to fix the race condition by adding these checks or just
adding these checks in case pm_runtime_get_sync() fails?

Can Guo.

> Add handling of the return value of pm_runtime_get_sync(). Let it 

> return

> in case pm_runtime_get_sync() resume failed.

> 

> Signed-off-by: Bean Huo <beanhuo@micron.com>

> ---

>  drivers/scsi/ufs/ufs-sysfs.c | 38 ++++++++++++++++++++++++++++++------

>  1 file changed, 32 insertions(+), 6 deletions(-)

> 

> diff --git a/drivers/scsi/ufs/ufs-sysfs.c 

> b/drivers/scsi/ufs/ufs-sysfs.c

> index 0e1438485133..8e5e36e01bee 100644

> --- a/drivers/scsi/ufs/ufs-sysfs.c

> +++ b/drivers/scsi/ufs/ufs-sysfs.c

> @@ -154,12 +154,17 @@ static ssize_t auto_hibern8_show(struct device 

> *dev,

>  				 struct device_attribute *attr, char *buf)

>  {

>  	u32 ahit;

> +	int ret;

>  	struct ufs_hba *hba = dev_get_drvdata(dev);

> 

>  	if (!ufshcd_is_auto_hibern8_supported(hba))

>  		return -EOPNOTSUPP;

> 

> -	pm_runtime_get_sync(hba->dev);

> +	ret = pm_runtime_get_sync(hba->dev);

> +	if (ret < 0) {

> +		pm_runtime_put_noidle(hba->dev);

> +		return ret;

> +	}

>  	ufshcd_hold(hba, false);

>  	ahit = ufshcd_readl(hba, REG_AUTO_HIBERNATE_IDLE_TIMER);

>  	ufshcd_release(hba);

> @@ -225,7 +230,12 @@ static ssize_t ufs_sysfs_read_desc_param(struct

> ufs_hba *hba,

>  	if (param_size > 8)

>  		return -EINVAL;

> 

> -	pm_runtime_get_sync(hba->dev);

> +	ret = pm_runtime_get_sync(hba->dev);

> +	if (ret < 0) {

> +		pm_runtime_put_noidle(hba->dev);

> +		return ret;

> +	}

> +

>  	ret = ufshcd_read_desc_param(hba, desc_id, desc_index,

>  				param_offset, desc_buf, param_size);

>  	pm_runtime_put_sync(hba->dev);

> @@ -594,7 +604,11 @@ static ssize_t _name##_show(struct device 

> *dev,				\

>  	desc_buf = kzalloc(QUERY_DESC_MAX_SIZE, GFP_ATOMIC);		\

>  	if (!desc_buf)                                                  \

>  		return -ENOMEM;                                         \

> -	pm_runtime_get_sync(hba->dev);					\

> +	ret = pm_runtime_get_sync(hba->dev);				\

> +	if (ret < 0) {							\

> +		pm_runtime_put_noidle(hba->dev);			\

> +		return ret;						\

> +	}								\

>  	ret = ufshcd_query_descriptor_retry(hba,			\

>  		UPIU_QUERY_OPCODE_READ_DESC, QUERY_DESC_IDN_DEVICE,	\

>  		0, 0, desc_buf, &desc_len);				\

> @@ -653,7 +667,11 @@ static ssize_t _name##_show(struct device 

> *dev,				\

>  	struct ufs_hba *hba = dev_get_drvdata(dev);			\

>  	if (ufshcd_is_wb_flags(QUERY_FLAG_IDN##_uname))			\

>  		index = ufshcd_wb_get_query_index(hba);			\

> -	pm_runtime_get_sync(hba->dev);					\

> +	ret = pm_runtime_get_sync(hba->dev);				\

> +	if (ret < 0) {							\

> +		pm_runtime_put_noidle(hba->dev);			\

> +		return ret;						\

> +	}								\

>  	ret = ufshcd_query_flag(hba, UPIU_QUERY_OPCODE_READ_FLAG,	\

>  		QUERY_FLAG_IDN##_uname, index, &flag);			\

>  	pm_runtime_put_sync(hba->dev);					\

> @@ -711,7 +729,11 @@ static ssize_t _name##_show(struct device 

> *dev,				\

>  	u8 index = 0;							\

>  	if (ufshcd_is_wb_attrs(QUERY_ATTR_IDN##_uname))			\

>  		index = ufshcd_wb_get_query_index(hba);			\

> -	pm_runtime_get_sync(hba->dev);					\

> +	ret = pm_runtime_get_sync(hba->dev);				\

> +	if (ret < 0) {							\

> +		pm_runtime_put_noidle(hba->dev);			\

> +		return ret;						\

> +	}								\

>  	ret = ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_READ_ATTR,	\

>  		QUERY_ATTR_IDN##_uname, index, 0, &value);		\

>  	pm_runtime_put_sync(hba->dev);					\

> @@ -850,7 +872,11 @@ static ssize_t

> dyn_cap_needed_attribute_show(struct device *dev,

>  	u8 lun = ufshcd_scsi_to_upiu_lun(sdev->lun);

>  	int ret;

> 

> -	pm_runtime_get_sync(hba->dev);

> +	ret = pm_runtime_get_sync(hba->dev);

> +	if (ret < 0) {

> +		pm_runtime_put_noidle(hba->dev);

> +		return ret;

> +	}

>  	ret = ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_READ_ATTR,

>  		QUERY_ATTR_IDN_DYN_CAP_NEEDED, lun, 0, &value);

>  	pm_runtime_put_sync(hba->dev);
Bean Huo Jan. 4, 2021, 5:39 p.m. UTC | #2
On Mon, 2020-12-28 at 09:50 +0800, Can Guo wrote:
> > The race issue may exist between UFS access in UFS sysfs context

> > and 

> > UFS

> > shutdown, thus will cause pm_runtime_get_sync() resume failure.

> 

> Are you trying to fix the race condition by adding these checks or

> just

> adding these checks in case pm_runtime_get_sync() fails?

> 

> Can Guo.


Can,
thanks for your review. Sorry, I didn't quite get your point.
This patch is just to add checkup in case pm_runtime_get_sync() failed.

what else should be added?

Bean