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scsi: ufshcd: Fix possible unclocked register access

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Vendor specific setup_clocks callback may require the clocks managed by
ufshcd driver to be ON. So if the vendor specific setup_clocks callback
is called while the required clocks are turned off, it could result into
unclocked register access.

To prevent possible unclock register access, this change adds one more
argument to setup_clocks callback to let it know whether it is called
pre/post the clock changes by core driver.

Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Reviewed-by: Kiwoong Kim <kwmad.kim@samsung.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Subhash Jadavani
2016-10-06 21:48:22 -07:00
committed by Martin K. Petersen
parent fd37f66eb6
commit 1e879e8fa9
3 changed files with 19 additions and 16 deletions
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10
drivers/scsi/ufs/ufs-qcom.c
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@@ -1094,10 +1094,12 @@ static void ufs_qcom_set_caps(struct ufs_hba *hba)
* ufs_qcom_setup_clocks - enables/disable clocks
* @hba: host controller instance
* @on: If true, enable clocks else disable them.
* @status: PRE_CHANGE or POST_CHANGE notify
*
* Returns 0 on success, non-zero on failure.
*/
static int ufs_qcom_setup_clocks(struct ufs_hba *hba, bool on)
static int ufs_qcom_setup_clocks(struct ufs_hba *hba, bool on,
enum ufs_notify_change_status status)
{
struct ufs_qcom_host *host = ufshcd_get_variant(hba);
int err;
@@ -1111,7 +1113,7 @@ static int ufs_qcom_setup_clocks(struct ufs_hba *hba, bool on)
if (!host)
return 0;
if (on) {
if (on && (status == POST_CHANGE)) {
err = ufs_qcom_phy_enable_iface_clk(host->generic_phy);
if (err)
goto out;
@@ -1130,7 +1132,7 @@ static int ufs_qcom_setup_clocks(struct ufs_hba *hba, bool on)
if (vote == host->bus_vote.min_bw_vote)
ufs_qcom_update_bus_bw_vote(host);
} else {
} else if (!on && (status == PRE_CHANGE)) {
/* M-PHY RMMI interface clocks can be turned off */
ufs_qcom_phy_disable_iface_clk(host->generic_phy);
@@ -1254,7 +1256,7 @@ static int ufs_qcom_init(struct ufs_hba *hba)
ufs_qcom_set_caps(hba);
ufs_qcom_advertise_quirks(hba);
ufs_qcom_setup_clocks(hba, true);
ufs_qcom_setup_clocks(hba, true, POST_CHANGE);
if (hba->dev->id < MAX_UFS_QCOM_HOSTS)
ufs_qcom_hosts[hba->dev->id] = host;