--
Hi Dear
My name is Lisa Williams, I am from United States of America, Its my
pleasure to contact you for new and special friendship, I will be glad
to see your reply for us to know each other better
Yours
Lisa Williams
The bug is here:
if (!iommu || iommu->dev->of_node != spec->np) {
The list iterator value 'iommu' will *always* be set and non-NULL by
list_for_each_entry(), so it is incorrect to assume that the iterator
value will be NULL if the list is empty or no element is found (in fact,
it will point to a invalid structure object containing HEAD).
To fix the bug, use a new value 'iter' as the list iterator, while use
the old value 'iommu' as a dedicated variable to point to the found one,
and remove the unneeded check for 'iommu->dev->of_node != spec->np'
outside the loop.
Cc: stable(a)vger.kernel.org
Fixes: f78ebca8ff3d6 ("iommu/msm: Add support for generic master bindings")
Signed-off-by: Xiaomeng Tong <xiam0nd.tong(a)gmail.com>
---
changes since v1:
- add a new iter variable (suggested by Joerg Roedel)
v1: https://lore.kernel.org/all/20220327053558.2821-1-xiam0nd.tong@gmail.com/
---
drivers/iommu/msm_iommu.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/drivers/iommu/msm_iommu.c b/drivers/iommu/msm_iommu.c
index 3a38352b603f..41a3231a6d13 100644
--- a/drivers/iommu/msm_iommu.c
+++ b/drivers/iommu/msm_iommu.c
@@ -615,16 +615,17 @@ static void insert_iommu_master(struct device *dev,
static int qcom_iommu_of_xlate(struct device *dev,
struct of_phandle_args *spec)
{
- struct msm_iommu_dev *iommu;
+ struct msm_iommu_dev *iommu = NULL, *iter;
unsigned long flags;
spin_lock_irqsave(&msm_iommu_lock, flags);
- list_for_each_entry(iommu, &qcom_iommu_devices, dev_node)
- if (iommu->dev->of_node == spec->np)
+ list_for_each_entry(iter, &qcom_iommu_devices, dev_node)
+ if (iter->dev->of_node == spec->np) {
+ iommu = iter;
break;
+ }
- if (!iommu || iommu->dev->of_node != spec->np) {
+ if (!iommu) {
ret = -ENODEV;
goto fail;
}
--
2.17.1
In ufs_qcom_dev_ref_clk_ctrl(), it was noted that the ref_clk needs to be
stable for at least 1us. Even though there is wmb() to make sure the write
gets "completed", there is no guarantee that the write actually reached
the UFS device. There is a good chance that the write could be stored in
a Write Buffer (WB). In that case, even though the CPU waits for 1us, the
ref_clk might not be stable for that period.
So lets do a readl() to make sure that the previous write has reached the
UFS device before udelay().
Also, the wmb() after writel_relaxed is not really needed. Both writel and
readl are ordered on all architectures and the CPU won't speculate
instructions after readl() due to the in-built control dependency with
read value on weakly ordered architectures. So it can be safely removed.
Cc: stable(a)vger.kernel.org
Fixes: f06fcc7155dc ("scsi: ufs-qcom: add QUniPro hardware support and power optimizations")
Reviewed-by: Bjorn Andersson <bjorn.andersson(a)linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam(a)linaro.org>
---
drivers/scsi/ufs/ufs-qcom.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
index 6126e50b9af4..b718c38fccc9 100644
--- a/drivers/scsi/ufs/ufs-qcom.c
+++ b/drivers/scsi/ufs/ufs-qcom.c
@@ -687,8 +687,11 @@ static void ufs_qcom_dev_ref_clk_ctrl(struct ufs_qcom_host *host, bool enable)
writel_relaxed(temp, host->dev_ref_clk_ctrl_mmio);
- /* ensure that ref_clk is enabled/disabled before we return */
- wmb();
+ /*
+ * Make sure the write to ref_clk reaches the destination and
+ * not stored in a Write Buffer (WB).
+ */
+ readl(host->dev_ref_clk_ctrl_mmio);
/*
* If we call hibern8 exit after this, we need to make sure that
--
2.25.1