On 2021-01-12 14:35, Stanley Chu wrote:
Hi Can,
On Sat, 2021-01-02 at 05:59 -0800, Can Guo wrote:
During system resume/suspend, hba could be NULL. In this case, do not
touch
eh_sem.
Fixes: 88a92d6ae4fe ("scsi: ufs: Serialize eh_work with system PM
events and async scan")
Signed-off-by: Can Guo <cang@xxxxxxxxxxxxxx>
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index e221add..9829c8d 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -94,6 +94,8 @@
16, 4, buf, __len, false); \
} while (0)
+static bool early_suspend;
+
int ufshcd_dump_regs(struct ufs_hba *hba, size_t offset, size_t len,
const char *prefix)
{
@@ -8896,8 +8898,14 @@ int ufshcd_system_suspend(struct ufs_hba *hba)
int ret = 0;
ktime_t start = ktime_get();
+ if (!hba) {
+ early_suspend = true;
+ return 0;
+ }
+
down(&hba->eh_sem);
- if (!hba || !hba->is_powered)
+
+ if (!hba->is_powered)
return 0;
if ((ufs_get_pm_lvl_to_dev_pwr_mode(hba->spm_lvl) ==
@@ -8945,9 +8953,12 @@ int ufshcd_system_resume(struct ufs_hba *hba)
int ret = 0;
ktime_t start = ktime_get();
- if (!hba) {
- up(&hba->eh_sem);
+ if (!hba)
return -EINVAL;
+
+ if (unlikely(early_suspend)) {
+ early_suspend = false;
+ down(&hba->eh_sem);
}
I guess early_suspend here is to handle the case that hba is null
during
ufshcd_system_suspend() but !null during ufshcd_system_resume(). If
yes,
would it be possible? If no, may I know what is the purpose?
Yes, you are right. I think it is possible. platform_set_drvdata()
is called in ufshcd_pltfrm_init(). Say suspend happens before
platform_set_drvdata() is called, but resume comes back after
platform_set_drvdata() is called. What do you think?
Thanks,
Can Guo.
Thanks a lot.
Stanley Chu
if (!hba->is_powered || pm_runtime_suspended(hba->dev))
