Commit 495184ac91bb ("mt76: mt7915: add support for applying
pre-calibration data") was fundamentally broken and never worked.
The idea (before NVMEM support) was to expand the MTD function and pass
an additional offset. For normal EEPROM load the offset would always be
0. For the purpose of precal loading, an offset was passed that was
internally the size of EEPROM, since precal data is right after the
EEPROM.
Problem is that the offset value passed is never handled and is actually
overwrite by
offset = be32_to_cpup(list);
ret = mtd_read(mtd, offset, len, &retlen, eep);
resulting in the passed offset value always ingnored. (and even passing
garbage data as precal as the start of the EEPROM is getting read)
Fix this by adding to the current offset value, the offset from DT to
correctly read the piece of data at the requested location.
Cc: stable(a)vger.kernel.org
Fixes: 495184ac91bb ("mt76: mt7915: add support for applying pre-calibration data")
Signed-off-by: Christian Marangi <ansuelsmth(a)gmail.com>
---
drivers/net/wireless/mediatek/mt76/eeprom.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/wireless/mediatek/mt76/eeprom.c b/drivers/net/wireless/mediatek/mt76/eeprom.c
index 36564930aef1..2558788f7ffb 100644
--- a/drivers/net/wireless/mediatek/mt76/eeprom.c
+++ b/drivers/net/wireless/mediatek/mt76/eeprom.c
@@ -67,7 +67,7 @@ static int mt76_get_of_epprom_from_mtd(struct mt76_dev *dev, void *eep, int offs
goto out_put_node;
}
- offset = be32_to_cpup(list);
+ offset += be32_to_cpup(list);
ret = mtd_read(mtd, offset, len, &retlen, eep);
put_mtd_device(mtd);
if (mtd_is_bitflip(ret))
--
2.40.1
> Now i wounder if you are fixing the wrong thing. Maybe you should be
> fixing the PHY so it does not report up and then down? You say 'very
> snall intervals', which should in fact be 1 second. So is the PHY
> reporting link for a number of poll intervals? 1min to 10 minutes?
>
> Andrew
>
> Yes, according to the log records, the phy polls every second,
> but the link status changes take time.
> Generally, it takes 10 seconds for the phy to detect link down,
> but occasionally it takes several minutes to detect link down,
What PHY driver is this?
It is not so clear what should actually happen with auto-neg turned
off. With it on, and the link going down, the PHY should react after
about 1 second. It is not supposed to react faster than that, although
some PHYs allow fast link down notification to be configured.
Have you checked 802.3 to see what it says about auto-neg off and link
down detection?
I personally would not suppress this behaviour in the MAC
driver. Otherwise you are going to have funny combinations of special
cases of a feature which very few people actually use, making your
maintenance costs higher.
Andrew
From: Krzysztof Kozlowski <krzysztof.kozlowski(a)linaro.org>
commit 6c2f421174273de8f83cde4286d1c076d43a2d35 upstream.
Several core drivers and buses expect that driver_override is a
dynamically allocated memory thus later they can kfree() it.
However such assumption is not documented, there were in the past and
there are already users setting it to a string literal. This leads to
kfree() of static memory during device release (e.g. in error paths or
during unbind):
kernel BUG at ../mm/slub.c:3960!
Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ARM
...
(kfree) from [<c058da50>] (platform_device_release+0x88/0xb4)
(platform_device_release) from [<c0585be0>] (device_release+0x2c/0x90)
(device_release) from [<c0a69050>] (kobject_put+0xec/0x20c)
(kobject_put) from [<c0f2f120>] (exynos5_clk_probe+0x154/0x18c)
(exynos5_clk_probe) from [<c058de70>] (platform_drv_probe+0x6c/0xa4)
(platform_drv_probe) from [<c058b7ac>] (really_probe+0x280/0x414)
(really_probe) from [<c058baf4>] (driver_probe_device+0x78/0x1c4)
(driver_probe_device) from [<c0589854>] (bus_for_each_drv+0x74/0xb8)
(bus_for_each_drv) from [<c058b48c>] (__device_attach+0xd4/0x16c)
(__device_attach) from [<c058a638>] (bus_probe_device+0x88/0x90)
(bus_probe_device) from [<c05871fc>] (device_add+0x3dc/0x62c)
(device_add) from [<c075ff10>] (of_platform_device_create_pdata+0x94/0xbc)
(of_platform_device_create_pdata) from [<c07600ec>] (of_platform_bus_create+0x1a8/0x4fc)
(of_platform_bus_create) from [<c0760150>] (of_platform_bus_create+0x20c/0x4fc)
(of_platform_bus_create) from [<c07605f0>] (of_platform_populate+0x84/0x118)
(of_platform_populate) from [<c0f3c964>] (of_platform_default_populate_init+0xa0/0xb8)
(of_platform_default_populate_init) from [<c01031f8>] (do_one_initcall+0x8c/0x404)
Provide a helper which clearly documents the usage of driver_override.
This will allow later to reuse the helper and reduce the amount of
duplicated code.
Convert the platform driver to use a new helper and make the
driver_override field const char (it is not modified by the core).
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki(a)intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki(a)intel.com>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski(a)linaro.org>
Link: https://lore.kernel.org/r/20220419113435.246203-2-krzysztof.kozlowski@linar…
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
Signed-off-by: Lee Jones <lee(a)kernel.org>
---
drivers/base/driver.c | 69 +++++++++++++++++++++++++++++++++
drivers/base/platform.c | 28 ++-----------
include/linux/device.h | 2 +
include/linux/platform_device.h | 6 ++-
4 files changed, 80 insertions(+), 25 deletions(-)
diff --git a/drivers/base/driver.c b/drivers/base/driver.c
index 857c8f1b876e5..668c6c8c22f1f 100644
--- a/drivers/base/driver.c
+++ b/drivers/base/driver.c
@@ -29,6 +29,75 @@ static struct device *next_device(struct klist_iter *i)
return dev;
}
+/**
+ * driver_set_override() - Helper to set or clear driver override.
+ * @dev: Device to change
+ * @override: Address of string to change (e.g. &device->driver_override);
+ * The contents will be freed and hold newly allocated override.
+ * @s: NUL-terminated string, new driver name to force a match, pass empty
+ * string to clear it ("" or "\n", where the latter is only for sysfs
+ * interface).
+ * @len: length of @s
+ *
+ * Helper to set or clear driver override in a device, intended for the cases
+ * when the driver_override field is allocated by driver/bus code.
+ *
+ * Returns: 0 on success or a negative error code on failure.
+ */
+int driver_set_override(struct device *dev, const char **override,
+ const char *s, size_t len)
+{
+ const char *new, *old;
+ char *cp;
+
+ if (!override || !s)
+ return -EINVAL;
+
+ /*
+ * The stored value will be used in sysfs show callback (sysfs_emit()),
+ * which has a length limit of PAGE_SIZE and adds a trailing newline.
+ * Thus we can store one character less to avoid truncation during sysfs
+ * show.
+ */
+ if (len >= (PAGE_SIZE - 1))
+ return -EINVAL;
+
+ if (!len) {
+ /* Empty string passed - clear override */
+ device_lock(dev);
+ old = *override;
+ *override = NULL;
+ device_unlock(dev);
+ kfree(old);
+
+ return 0;
+ }
+
+ cp = strnchr(s, len, '\n');
+ if (cp)
+ len = cp - s;
+
+ new = kstrndup(s, len, GFP_KERNEL);
+ if (!new)
+ return -ENOMEM;
+
+ device_lock(dev);
+ old = *override;
+ if (cp != s) {
+ *override = new;
+ } else {
+ /* "\n" passed - clear override */
+ kfree(new);
+ *override = NULL;
+ }
+ device_unlock(dev);
+
+ kfree(old);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(driver_set_override);
+
/**
* driver_for_each_device - Iterator for devices bound to a driver.
* @drv: Driver we're iterating.
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 2f89e618b142c..a09e7a681f7a7 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -891,31 +891,11 @@ static ssize_t driver_override_store(struct device *dev,
const char *buf, size_t count)
{
struct platform_device *pdev = to_platform_device(dev);
- char *driver_override, *old, *cp;
-
- /* We need to keep extra room for a newline */
- if (count >= (PAGE_SIZE - 1))
- return -EINVAL;
-
- driver_override = kstrndup(buf, count, GFP_KERNEL);
- if (!driver_override)
- return -ENOMEM;
-
- cp = strchr(driver_override, '\n');
- if (cp)
- *cp = '\0';
-
- device_lock(dev);
- old = pdev->driver_override;
- if (strlen(driver_override)) {
- pdev->driver_override = driver_override;
- } else {
- kfree(driver_override);
- pdev->driver_override = NULL;
- }
- device_unlock(dev);
+ int ret;
- kfree(old);
+ ret = driver_set_override(dev, &pdev->driver_override, buf, count);
+ if (ret)
+ return ret;
return count;
}
diff --git a/include/linux/device.h b/include/linux/device.h
index 37e359d81a86f..bccd367c11de5 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -330,6 +330,8 @@ extern int __must_check driver_create_file(struct device_driver *driver,
extern void driver_remove_file(struct device_driver *driver,
const struct driver_attribute *attr);
+int driver_set_override(struct device *dev, const char **override,
+ const char *s, size_t len);
extern int __must_check driver_for_each_device(struct device_driver *drv,
struct device *start,
void *data,
diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h
index 9e5c98fcea8c6..8268439975b21 100644
--- a/include/linux/platform_device.h
+++ b/include/linux/platform_device.h
@@ -29,7 +29,11 @@ struct platform_device {
struct resource *resource;
const struct platform_device_id *id_entry;
- char *driver_override; /* Driver name to force a match */
+ /*
+ * Driver name to force a match. Do not set directly, because core
+ * frees it. Use driver_set_override() to set or clear it.
+ */
+ const char *driver_override;
/* MFD cell pointer */
struct mfd_cell *mfd_cell;
--
2.42.0.655.g421f12c284-goog
From: Krzysztof Kozlowski <krzysztof.kozlowski(a)linaro.org>
commit 6c2f421174273de8f83cde4286d1c076d43a2d35 upstream.
Several core drivers and buses expect that driver_override is a
dynamically allocated memory thus later they can kfree() it.
However such assumption is not documented, there were in the past and
there are already users setting it to a string literal. This leads to
kfree() of static memory during device release (e.g. in error paths or
during unbind):
kernel BUG at ../mm/slub.c:3960!
Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ARM
...
(kfree) from [<c058da50>] (platform_device_release+0x88/0xb4)
(platform_device_release) from [<c0585be0>] (device_release+0x2c/0x90)
(device_release) from [<c0a69050>] (kobject_put+0xec/0x20c)
(kobject_put) from [<c0f2f120>] (exynos5_clk_probe+0x154/0x18c)
(exynos5_clk_probe) from [<c058de70>] (platform_drv_probe+0x6c/0xa4)
(platform_drv_probe) from [<c058b7ac>] (really_probe+0x280/0x414)
(really_probe) from [<c058baf4>] (driver_probe_device+0x78/0x1c4)
(driver_probe_device) from [<c0589854>] (bus_for_each_drv+0x74/0xb8)
(bus_for_each_drv) from [<c058b48c>] (__device_attach+0xd4/0x16c)
(__device_attach) from [<c058a638>] (bus_probe_device+0x88/0x90)
(bus_probe_device) from [<c05871fc>] (device_add+0x3dc/0x62c)
(device_add) from [<c075ff10>] (of_platform_device_create_pdata+0x94/0xbc)
(of_platform_device_create_pdata) from [<c07600ec>] (of_platform_bus_create+0x1a8/0x4fc)
(of_platform_bus_create) from [<c0760150>] (of_platform_bus_create+0x20c/0x4fc)
(of_platform_bus_create) from [<c07605f0>] (of_platform_populate+0x84/0x118)
(of_platform_populate) from [<c0f3c964>] (of_platform_default_populate_init+0xa0/0xb8)
(of_platform_default_populate_init) from [<c01031f8>] (do_one_initcall+0x8c/0x404)
Provide a helper which clearly documents the usage of driver_override.
This will allow later to reuse the helper and reduce the amount of
duplicated code.
Convert the platform driver to use a new helper and make the
driver_override field const char (it is not modified by the core).
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki(a)intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki(a)intel.com>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski(a)linaro.org>
Link: https://lore.kernel.org/r/20220419113435.246203-2-krzysztof.kozlowski@linar…
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
Signed-off-by: Lee Jones <lee(a)kernel.org>
---
drivers/base/driver.c | 69 +++++++++++++++++++++++++++++++++
drivers/base/platform.c | 28 ++-----------
include/linux/device/driver.h | 2 +
include/linux/platform_device.h | 6 ++-
4 files changed, 80 insertions(+), 25 deletions(-)
diff --git a/drivers/base/driver.c b/drivers/base/driver.c
index 8c0d33e182fd5..1b9d47b10bd0a 100644
--- a/drivers/base/driver.c
+++ b/drivers/base/driver.c
@@ -30,6 +30,75 @@ static struct device *next_device(struct klist_iter *i)
return dev;
}
+/**
+ * driver_set_override() - Helper to set or clear driver override.
+ * @dev: Device to change
+ * @override: Address of string to change (e.g. &device->driver_override);
+ * The contents will be freed and hold newly allocated override.
+ * @s: NUL-terminated string, new driver name to force a match, pass empty
+ * string to clear it ("" or "\n", where the latter is only for sysfs
+ * interface).
+ * @len: length of @s
+ *
+ * Helper to set or clear driver override in a device, intended for the cases
+ * when the driver_override field is allocated by driver/bus code.
+ *
+ * Returns: 0 on success or a negative error code on failure.
+ */
+int driver_set_override(struct device *dev, const char **override,
+ const char *s, size_t len)
+{
+ const char *new, *old;
+ char *cp;
+
+ if (!override || !s)
+ return -EINVAL;
+
+ /*
+ * The stored value will be used in sysfs show callback (sysfs_emit()),
+ * which has a length limit of PAGE_SIZE and adds a trailing newline.
+ * Thus we can store one character less to avoid truncation during sysfs
+ * show.
+ */
+ if (len >= (PAGE_SIZE - 1))
+ return -EINVAL;
+
+ if (!len) {
+ /* Empty string passed - clear override */
+ device_lock(dev);
+ old = *override;
+ *override = NULL;
+ device_unlock(dev);
+ kfree(old);
+
+ return 0;
+ }
+
+ cp = strnchr(s, len, '\n');
+ if (cp)
+ len = cp - s;
+
+ new = kstrndup(s, len, GFP_KERNEL);
+ if (!new)
+ return -ENOMEM;
+
+ device_lock(dev);
+ old = *override;
+ if (cp != s) {
+ *override = new;
+ } else {
+ /* "\n" passed - clear override */
+ kfree(new);
+ *override = NULL;
+ }
+ device_unlock(dev);
+
+ kfree(old);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(driver_set_override);
+
/**
* driver_for_each_device - Iterator for devices bound to a driver.
* @drv: Driver we're iterating.
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 88aef93eb4ddf..647066229fec3 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -1046,31 +1046,11 @@ static ssize_t driver_override_store(struct device *dev,
const char *buf, size_t count)
{
struct platform_device *pdev = to_platform_device(dev);
- char *driver_override, *old, *cp;
-
- /* We need to keep extra room for a newline */
- if (count >= (PAGE_SIZE - 1))
- return -EINVAL;
-
- driver_override = kstrndup(buf, count, GFP_KERNEL);
- if (!driver_override)
- return -ENOMEM;
-
- cp = strchr(driver_override, '\n');
- if (cp)
- *cp = '\0';
-
- device_lock(dev);
- old = pdev->driver_override;
- if (strlen(driver_override)) {
- pdev->driver_override = driver_override;
- } else {
- kfree(driver_override);
- pdev->driver_override = NULL;
- }
- device_unlock(dev);
+ int ret;
- kfree(old);
+ ret = driver_set_override(dev, &pdev->driver_override, buf, count);
+ if (ret)
+ return ret;
return count;
}
diff --git a/include/linux/device/driver.h b/include/linux/device/driver.h
index ee7ba5b5417e5..a44f5adeaef5a 100644
--- a/include/linux/device/driver.h
+++ b/include/linux/device/driver.h
@@ -150,6 +150,8 @@ extern int __must_check driver_create_file(struct device_driver *driver,
extern void driver_remove_file(struct device_driver *driver,
const struct driver_attribute *attr);
+int driver_set_override(struct device *dev, const char **override,
+ const char *s, size_t len);
extern int __must_check driver_for_each_device(struct device_driver *drv,
struct device *start,
void *data,
diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h
index 17f9cd5626c83..e7a83b0218077 100644
--- a/include/linux/platform_device.h
+++ b/include/linux/platform_device.h
@@ -30,7 +30,11 @@ struct platform_device {
struct resource *resource;
const struct platform_device_id *id_entry;
- char *driver_override; /* Driver name to force a match */
+ /*
+ * Driver name to force a match. Do not set directly, because core
+ * frees it. Use driver_set_override() to set or clear it.
+ */
+ const char *driver_override;
/* MFD cell pointer */
struct mfd_cell *mfd_cell;
--
2.42.0.655.g421f12c284-goog
Commit 495184ac91bb ("mt76: mt7915: add support for applying
pre-calibration data") was fundamentally broken and never worked.
The idea (before NVMEM support) was to expand the MTD function and pass
an additional offset. For normal EEPROM load the offset would always be
0. For the purpose of precal loading, an offset was passed that was
internally the size of EEPROM, since precal data is right after the
EEPROM.
Problem is that the offset value passed is never handled and is actually
overwrite by
offset = be32_to_cpup(list);
ret = mtd_read(mtd, offset, len, &retlen, eep);
resulting in the passed offset value always ingnored. (and even passing
garbage data as precal as the start of the EEPROM is getting read)
Fix this by adding to the current offset value, the offset from DT to
correctly read the piece of data at the requested location.
Cc: stable(a)vger.kernel.org
Fixes: 495184ac91bb ("mt76: mt7915: add support for applying pre-calibration data")
Signed-off-by: Christian Marangi <ansuelsmth(a)gmail.com>
---
drivers/net/wireless/mediatek/mt76/eeprom.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/wireless/mediatek/mt76/eeprom.c b/drivers/net/wireless/mediatek/mt76/eeprom.c
index 36564930aef1..2558788f7ffb 100644
--- a/drivers/net/wireless/mediatek/mt76/eeprom.c
+++ b/drivers/net/wireless/mediatek/mt76/eeprom.c
@@ -67,7 +67,7 @@ static int mt76_get_of_epprom_from_mtd(struct mt76_dev *dev, void *eep, int offs
goto out_put_node;
}
- offset = be32_to_cpup(list);
+ offset += be32_to_cpup(list);
ret = mtd_read(mtd, offset, len, &retlen, eep);
put_mtd_device(mtd);
if (mtd_is_bitflip(ret))
--
2.40.1
Don't apply the stimer's counter side effects when modifying its
value from user-space, as this may trigger spurious interrupts.
For example:
- The stimer is configured in auto-enable mode.
- The stimer's count is set and the timer enabled.
- The stimer expires, an interrupt is injected.
- The VM is live migrated.
- The stimer config and count are deserialized, auto-enable is ON, the
stimer is re-enabled.
- The stimer expires right away, and injects an unwarranted interrupt.
Cc: stable(a)vger.kernel.org
Fixes: 1f4b34f825e8 ("kvm/x86: Hyper-V SynIC timers")
Signed-off-by: Nicolas Saenz Julienne <nsaenz(a)amazon.com>
---
Changes since v2:
- reword commit message/subject.
Changes since v1:
- Cover all 'stimer->config.enable' updates.
arch/x86/kvm/hyperv.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index 7c2dac6824e2..238afd7335e4 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -727,10 +727,12 @@ static int stimer_set_count(struct kvm_vcpu_hv_stimer *stimer, u64 count,
stimer_cleanup(stimer);
stimer->count = count;
- if (stimer->count == 0)
- stimer->config.enable = 0;
- else if (stimer->config.auto_enable)
- stimer->config.enable = 1;
+ if (!host) {
+ if (stimer->count == 0)
+ stimer->config.enable = 0;
+ else if (stimer->config.auto_enable)
+ stimer->config.enable = 1;
+ }
if (stimer->config.enable)
stimer_mark_pending(stimer, false);
--
2.40.1