[PATCH AUTOSEL 4.19 55/56] scsi: ufs: ufs-qcom: Fix race conditions caused by ufs_qcom_testbus_config()

From: Sasha Levin
Date: Sun Oct 18 2020 - 15:37:24 EST


From: Can Guo <cang@xxxxxxxxxxxxxx>

[ Upstream commit 89dd87acd40a44de8ff3358138aedf8f73f4efc6 ]

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 a race condition. Fix this by removing the
unnecessary calls of pm_runtime_get_sync() and ufshcd_hold().

Link: https://lore.kernel.org/r/1596975355-39813-3-git-send-email-cang@xxxxxxxxxxxxxx
Reviewed-by: Hongwu Su <hongwus@xxxxxxxxxxxxxx>
Reviewed-by: Avri Altman <avri.altman@xxxxxxx>
Reviewed-by: Bean Huo <beanhuo@xxxxxxxxxx>
Reviewed-by: Asutosh Das <asutoshd@xxxxxxxxxxxxxx>
Signed-off-by: Can Guo <cang@xxxxxxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/scsi/ufs/ufs-qcom.c | 5 -----
1 file changed, 5 deletions(-)

diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
index 21e3ff590ec91..798a74535ea7b 100644
--- a/drivers/scsi/ufs/ufs-qcom.c
+++ b/drivers/scsi/ufs/ufs-qcom.c
@@ -1581,9 +1581,6 @@ 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);
@@ -1596,8 +1593,6 @@ 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;
}
--
2.25.1