[PATCH 4.14 117/246] scsi: ufs: ufshcd: fix possible unclocked register access
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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2018-08-01 17:17:40
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4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Subhash Jadavani <redacted> [ Upstream commit b334456ec2021b1addc19806990115e69ec4ac32 ] Vendor specific setup_clocks ops may depend on clocks managed by ufshcd driver so if the vendor specific setup_clocks callback is called when the required clocks are turned off, it results into unclocked register access. This change make sure that required clocks are enabled before vendor specific setup_clocks callback is called. Signed-off-by: Subhash Jadavani <redacted> Signed-off-by: Venkat Gopalakrishnan <redacted> Signed-off-by: Can Guo <redacted> Signed-off-by: Asutosh Das <redacted> Signed-off-by: Martin K. Petersen <redacted> Signed-off-by: Sasha Levin <redacted> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/scsi/ufs/ufshcd.c | 26 ++++++++++++++++++++------ 1 file changed, 20 insertions(+), 6 deletions(-)
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c@@ -6761,9 +6761,16 @@ static int __ufshcd_setup_clocks(struct if (list_empty(head)) goto out; - ret = ufshcd_vops_setup_clocks(hba, on, PRE_CHANGE); - if (ret) - return ret; + /* + * vendor specific setup_clocks ops may depend on clocks managed by + * this standard driver hence call the vendor specific setup_clocks + * before disabling the clocks managed here. + */ + if (!on) { + ret = ufshcd_vops_setup_clocks(hba, on, PRE_CHANGE); + if (ret) + return ret; + } list_for_each_entry(clki, head, list) { if (!IS_ERR_OR_NULL(clki->clk)) {
@@ -6787,9 +6794,16 @@ static int __ufshcd_setup_clocks(struct } } - ret = ufshcd_vops_setup_clocks(hba, on, POST_CHANGE); - if (ret) - return ret; + /* + * vendor specific setup_clocks ops may depend on clocks managed by + * this standard driver hence call the vendor specific setup_clocks + * after enabling the clocks managed here. + */ + if (on) { + ret = ufshcd_vops_setup_clocks(hba, on, POST_CHANGE); + if (ret) + return ret; + } out: if (ret) {