Make sure to drop the reference taken to the iommu platform device when
looking up its driver data during probe_device().
Fixes: b17336c55d89 ("iommu/mediatek: add support for mtk iommu generation one HW")
Cc: stable(a)vger.kernel.org # 4.8
Cc: Honghui Zhang <honghui.zhang(a)mediatek.com>
Signed-off-by: Johan Hovold <johan(a)kernel.org>
---
drivers/iommu/mtk_iommu_v1.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c
index 10cc0b1197e8..de9153c0a82f 100644
--- a/drivers/iommu/mtk_iommu_v1.c
+++ b/drivers/iommu/mtk_iommu_v1.c
@@ -435,6 +435,8 @@ static int mtk_iommu_v1_create_mapping(struct device *dev,
return -EINVAL;
dev_iommu_priv_set(dev, platform_get_drvdata(m4updev));
+
+ put_device(&m4updev->dev);
}
ret = iommu_fwspec_add_ids(dev, args->args, 1);
--
2.49.1
Make sure to drop the reference taken to the iommu platform device when
looking up its driver data during of_xlate().
Fixes: 7b2d59611fef ("iommu/ipmmu-vmsa: Replace local utlb code with fwspec ids")
Cc: stable(a)vger.kernel.org # 4.14
Cc: Magnus Damm <damm+renesas(a)opensource.se>
Signed-off-by: Johan Hovold <johan(a)kernel.org>
---
drivers/iommu/ipmmu-vmsa.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/iommu/ipmmu-vmsa.c b/drivers/iommu/ipmmu-vmsa.c
index ffa892f65714..02a2a55ffa0a 100644
--- a/drivers/iommu/ipmmu-vmsa.c
+++ b/drivers/iommu/ipmmu-vmsa.c
@@ -720,6 +720,8 @@ static int ipmmu_init_platform_device(struct device *dev,
dev_iommu_priv_set(dev, platform_get_drvdata(ipmmu_pdev));
+ put_device(&ipmmu_pdev->dev);
+
return 0;
}
--
2.49.1
Make sure to drop the reference taken to the iommu platform device when
looking up its driver data during of_xlate().
Fixes: aa759fd376fb ("iommu/exynos: Add callback for initializing devices from device tree")
Cc: stable(a)vger.kernel.org # 4.2
Cc: Marek Szyprowski <m.szyprowski(a)samsung.com>
Signed-off-by: Johan Hovold <johan(a)kernel.org>
---
drivers/iommu/exynos-iommu.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)
diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
index b6edd178fe25..ce9e935cb84c 100644
--- a/drivers/iommu/exynos-iommu.c
+++ b/drivers/iommu/exynos-iommu.c
@@ -1446,17 +1446,14 @@ static int exynos_iommu_of_xlate(struct device *dev,
return -ENODEV;
data = platform_get_drvdata(sysmmu);
- if (!data) {
- put_device(&sysmmu->dev);
+ put_device(&sysmmu->dev);
+ if (!data)
return -ENODEV;
- }
if (!owner) {
owner = kzalloc(sizeof(*owner), GFP_KERNEL);
- if (!owner) {
- put_device(&sysmmu->dev);
+ if (!owner)
return -ENOMEM;
- }
INIT_LIST_HEAD(&owner->controllers);
mutex_init(&owner->rpm_lock);
--
2.49.1
Make sure to drop the reference taken to the iommu platform device when
looking up its driver data during of_xlate().
Note that commit e2eae09939a8 ("iommu/qcom: add missing put_device()
call in qcom_iommu_of_xlate()") fixed the leak in a couple of error
paths, but the reference is still leaking on success and late failures.
Fixes: 0ae349a0f33f ("iommu/qcom: Add qcom_iommu")
Cc: stable(a)vger.kernel.org # 4.14: e2eae09939a8
Cc: Rob Clark <robin.clark(a)oss.qualcomm.com>
Cc: Yu Kuai <yukuai3(a)huawei.com>
Signed-off-by: Johan Hovold <johan(a)kernel.org>
---
drivers/iommu/arm/arm-smmu/qcom_iommu.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/drivers/iommu/arm/arm-smmu/qcom_iommu.c b/drivers/iommu/arm/arm-smmu/qcom_iommu.c
index c5be95e56031..9c1166a3af6c 100644
--- a/drivers/iommu/arm/arm-smmu/qcom_iommu.c
+++ b/drivers/iommu/arm/arm-smmu/qcom_iommu.c
@@ -565,14 +565,14 @@ static int qcom_iommu_of_xlate(struct device *dev,
qcom_iommu = platform_get_drvdata(iommu_pdev);
+ put_device(&iommu_pdev->dev);
+
/* make sure the asid specified in dt is valid, so we don't have
* to sanity check this elsewhere:
*/
if (WARN_ON(asid > qcom_iommu->max_asid) ||
- WARN_ON(qcom_iommu->ctxs[asid] == NULL)) {
- put_device(&iommu_pdev->dev);
+ WARN_ON(qcom_iommu->ctxs[asid] == NULL))
return -EINVAL;
- }
if (!dev_iommu_priv_get(dev)) {
dev_iommu_priv_set(dev, qcom_iommu);
@@ -581,10 +581,8 @@ static int qcom_iommu_of_xlate(struct device *dev,
* multiple different iommu devices. Multiple context
* banks are ok, but multiple devices are not:
*/
- if (WARN_ON(qcom_iommu != dev_iommu_priv_get(dev))) {
- put_device(&iommu_pdev->dev);
+ if (WARN_ON(qcom_iommu != dev_iommu_priv_get(dev)))
return -EINVAL;
- }
}
return iommu_fwspec_add_ids(dev, &asid, 1);
--
2.49.1
Make sure to drop the reference taken to the iommu platform device when
looking up its driver data during of_xlate().
Fixes: 46d1fb072e76 ("iommu/dart: Add DART iommu driver")
Cc: stable(a)vger.kernel.org # 5.15
Cc: Sven Peter <sven(a)kernel.org>
Signed-off-by: Johan Hovold <johan(a)kernel.org>
---
drivers/iommu/apple-dart.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/iommu/apple-dart.c b/drivers/iommu/apple-dart.c
index 190f28d76615..1aa7c10262a8 100644
--- a/drivers/iommu/apple-dart.c
+++ b/drivers/iommu/apple-dart.c
@@ -790,6 +790,8 @@ static int apple_dart_of_xlate(struct device *dev,
struct apple_dart *cfg_dart;
int i, sid;
+ put_device(&iommu_pdev->dev);
+
if (args->args_count != 1)
return -EINVAL;
sid = args->args[0];
--
2.49.1
From: Shawn Guo <shawnguo(a)kernel.org>
A regression is seen with 6.6 -> 6.12 kernel upgrade on platforms where
cpufreq-dt driver sets cpuinfo.transition_latency as CPUFREQ_ETERNAL (-1),
due to that platform's DT doesn't provide the optional property
'clock-latency-ns'. The dbs sampling_rate was 10000 us on 6.6 and
suddently becomes 6442450 us (4294967295 / 1000 * 1.5) on 6.12 for these
platforms, because the default transition delay was dropped by the commits
below.
commit 37c6dccd6837 ("cpufreq: Remove LATENCY_MULTIPLIER")
commit a755d0e2d41b ("cpufreq: Honour transition_latency over transition_delay_us")
commit e13aa799c2a6 ("cpufreq: Change default transition delay to 2ms")
It slows down dbs governor's reacting to CPU loading change
dramatically. Also, as transition_delay_us is used by schedutil governor
as rate_limit_us, it shows a negative impact on device idle power
consumption, because the device gets slightly less time in the lowest OPP.
Fix the regressions by defining a default transition latency for
handling the case of CPUFREQ_ETERNAL.
Cc: stable(a)vger.kernel.org
Fixes: 37c6dccd6837 ("cpufreq: Remove LATENCY_MULTIPLIER")
Signed-off-by: Shawn Guo <shawnguo(a)kernel.org>
---
Changes for v2:
- Follow Rafael's suggestion to define a default transition latency for
handling CPUFREQ_ETERNAL, and pave the way to get rid of
CPUFREQ_ETERNAL completely later.
v1: https://lkml.org/lkml/2025/9/10/294
drivers/cpufreq/cpufreq.c | 3 +++
include/linux/cpufreq.h | 2 ++
2 files changed, 5 insertions(+)
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index fc7eace8b65b..c69d10f0e8ec 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -549,6 +549,9 @@ unsigned int cpufreq_policy_transition_delay_us(struct cpufreq_policy *policy)
if (policy->transition_delay_us)
return policy->transition_delay_us;
+ if (policy->cpuinfo.transition_latency == CPUFREQ_ETERNAL)
+ policy->cpuinfo.transition_latency = CPUFREQ_DEFAULT_TANSITION_LATENCY_NS;
+
latency = policy->cpuinfo.transition_latency / NSEC_PER_USEC;
if (latency)
/* Give a 50% breathing room between updates */
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index 95f3807c8c55..935e9a660039 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -36,6 +36,8 @@
/* Print length for names. Extra 1 space for accommodating '\n' in prints */
#define CPUFREQ_NAME_PLEN (CPUFREQ_NAME_LEN + 1)
+#define CPUFREQ_DEFAULT_TANSITION_LATENCY_NS NSEC_PER_MSEC
+
struct cpufreq_governor;
enum cpufreq_table_sorting {
--
2.43.0
