Hi Bart,
On 2020-07-14 11:47, Bart Van Assche wrote:
On 2020-07-13 19:28, Can Guo 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.
Meanwhile, if ufs_qcom_dump_dbg_regs() calls ufs_qcom_testbus_config()
from
ufshcd_suspend/resume and/or clk gate/ungate context,
pm_runtime_get_sync()
and ufshcd_hold() will cause racing problems. Fix it by removing the
unnecessary calls of pm_runtime_get_sync() and ufshcd_hold().
Signed-off-by: Can Guo <cang@xxxxxxxxxxxxxx>
---
drivers/scsi/ufs/ufs-qcom.c | 17 +++++++----------
1 file changed, 7 insertions(+), 10 deletions(-)
diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
index 2e6ddb5..3743c17 100644
--- a/drivers/scsi/ufs/ufs-qcom.c
+++ b/drivers/scsi/ufs/ufs-qcom.c
@@ -1604,9 +1604,6 @@ int ufs_qcom_testbus_config(struct ufs_qcom_host
*host)
*/
}
mask <<= offset;
-
- pm_runtime_get_sync(host->hba->dev);
- ufshcd_hold(host->hba, false);
ufshcd_rmwl(host->hba, TEST_BUS_SEL,
(u32)host->testbus.select_major << 19,
REG_UFS_CFG1);
@@ -1619,8 +1616,6 @@ int ufs_qcom_testbus_config(struct ufs_qcom_host
*host)
* committed before returning.
*/
mb();
- ufshcd_release(host->hba);
- pm_runtime_put_sync(host->hba->dev);
return 0;
}
@@ -1658,11 +1653,13 @@ static void ufs_qcom_dump_dbg_regs(struct
ufs_hba *hba)
/* 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()) {
+ udelay(1000);
+ ufs_qcom_testbus_read(hba);
+ udelay(1000);
+ ufs_qcom_print_unipro_testbus(hba);
+ udelay(1000);
+ }
}
It is not clear to me how udelay() calls can help in code that takes
long
since these functions use busy-waiting? Should the udelay() calls
perhaps
be changed into cond_resched() calls?
Thanks,
Bart.
Maybe you are right, but this is not the purpose of this change. I am
just
trying to make sure this func can be invoked from any contexts without
making troubles like schedule while atomic and/or race conditions.
Thanks,
Can Guo.
