[PATCH 0/3] scsi: ufs: fix several issues caused by driver reloading

[PATCH 0/3] scsi: ufs: fix several issues caused by driver reloading

[Akinobu Mita]

This patch set addresses several issues caused by driver reloading in
ufs driver, although the first patch also fixes error path in driver
probe.

Akinobu Mita (3):
  scsi: ufs: avoid using hostdata after scsi_host_put()
  scsi: ufs: fix unbalanced power.usage_count after reloading driver
  scsi: ufs: fix unbalanced power.disable_depth after reloading driver

 drivers/scsi/ufs/ufshcd-pltfrm.c | 5 +++++
 drivers/scsi/ufs/ufshcd.c        | 6 +++---
 2 files changed, 8 insertions(+), 3 deletions(-)

-- 
1.9.1

[PATCH 1/3] scsi: ufs: avoid using hostdata after scsi_host_put()

[Akinobu Mita]

The hostdata array, which is denoted by 'hba' in ufs driver, should
not be accessed after calling scsi_host_put().

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Vinayak Holikatti <vinholikatti@gmail.com>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dolev Raviv <draviv@codeaurora.org>
Cc: Sujit Reddy Thumma <sthumma@codeaurora.org>
Cc: Subhash Jadavani <subhashj@codeaurora.org>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Sahitya Tummala <stummala@codeaurora.org>
Cc: linux-scsi@vger.kernel.org
---
 drivers/scsi/ufs/ufshcd.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 5d60a86..4e4de32 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -5239,12 +5239,12 @@ void ufshcd_remove(struct ufs_hba *hba)
 	ufshcd_disable_intr(hba, hba->intr_mask);
 	ufshcd_hba_stop(hba);
 
-	scsi_host_put(hba->host);
-
 	ufshcd_exit_clk_gating(hba);
 	if (ufshcd_is_clkscaling_enabled(hba))
 		devfreq_remove_device(hba->devfreq);
 	ufshcd_hba_exit(hba);
+
+	scsi_host_put(hba->host);
 }
 EXPORT_SYMBOL_GPL(ufshcd_remove);
 
@@ -5547,9 +5547,9 @@ exit_gating:
 	ufshcd_exit_clk_gating(hba);
 out_disable:
 	hba->is_irq_enabled = false;
-	scsi_host_put(host);
 	ufshcd_hba_exit(hba);
 out_error:
+	scsi_host_put(host);
 	return err;
 }
 EXPORT_SYMBOL_GPL(ufshcd_init);
-- 
1.9.1

[PATCH 2/3] scsi: ufs: fix unbalanced power.usage_count after reloading driver

[Akinobu Mita]

On driver removal, pm_runtime_get_sync() is called, but
pm_runtime_put_sync() is missed.  So once the driver is reloaded, the
device's power.usage_count is unbalanced and the idle callback for the
device will never be called.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Vinayak Holikatti <vinholikatti@gmail.com>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dolev Raviv <draviv@codeaurora.org>
Cc: Sujit Reddy Thumma <sthumma@codeaurora.org>
Cc: Subhash Jadavani <subhashj@codeaurora.org>
Cc: Maya Erez <merez@codeaurora.org>
Cc: Sahitya Tummala <stummala@codeaurora.org>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: linux-scsi@vger.kernel.org
---
 drivers/scsi/ufs/ufshcd-pltfrm.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/scsi/ufs/ufshcd-pltfrm.c b/drivers/scsi/ufs/ufshcd-pltfrm.c
index 7db9564..4164108 100644
--- a/drivers/scsi/ufs/ufshcd-pltfrm.c
+++ b/drivers/scsi/ufs/ufshcd-pltfrm.c
@@ -368,6 +368,7 @@ static int ufshcd_pltfrm_remove(struct platform_device *pdev)
 
 	pm_runtime_get_sync(&(pdev)->dev);
 	ufshcd_remove(hba);
+	pm_runtime_put_sync(&pdev->dev);
 	return 0;
 }
 
-- 
1.9.1

[PATCH 3/3] scsi: ufs: fix unbalanced power.disable_depth after reloading driver

[Akinobu Mita]

Every time the driver is reloaded, the warning message
"Unbalanced pm_runtime_enable!" is triggered due to unbalanced
power.disable_depth.  This is because pm_runtime_enable() is called
during driver probe but pm_runtime_disable() is missed on driver remove.

This also restores the device's runtime PM status to 'suspended' on
driver remove as it was set to 'active' during driver probe.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Vinayak Holikatti <vinholikatti@gmail.com>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dolev Raviv <draviv@codeaurora.org>
Cc: Sujit Reddy Thumma <sthumma@codeaurora.org>
Cc: Maya Erez <merez@codeaurora.org>
Cc: Raviv Shvili <rshvili@codeaurora.org>
Cc: Sahitya Tummala <stummala@codeaurora.org>
Cc: Subhash Jadavani <subhashj@codeaurora.org>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: linux-scsi@vger.kernel.org
---
 drivers/scsi/ufs/ufshcd-pltfrm.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/scsi/ufs/ufshcd-pltfrm.c b/drivers/scsi/ufs/ufshcd-pltfrm.c
index 4164108..b91cf09c 100644
--- a/drivers/scsi/ufs/ufshcd-pltfrm.c
+++ b/drivers/scsi/ufs/ufshcd-pltfrm.c
@@ -369,6 +369,10 @@ static int ufshcd_pltfrm_remove(struct platform_device *pdev)
 	pm_runtime_get_sync(&(pdev)->dev);
 	ufshcd_remove(hba);
 	pm_runtime_put_sync(&pdev->dev);
+
+	pm_runtime_disable(&pdev->dev);
+	pm_runtime_set_suspended(&pdev->dev);
+
 	return 0;
 }
 
-- 
1.9.1