Messages in this thread Patch in this message | | | From | Abhijit Gangurde <> | Subject | [PATCH v7 6/7] cdx: add sysfs for bus reset | Date | Tue, 17 Oct 2023 21:35:04 +0530 |
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Add sysfs interface reset to reset all the devices on the CDX bus.
Signed-off-by: Abhijit Gangurde <abhijit.gangurde@amd.com> --- Changes in v7: - None
Changes in v6: - Remove reset bus attribute - Use reset attribute of cdx device for bus reset.
Changes in v5: - None
Changes in v4: - None
Changes in v3: - None
Changes in v2: - Improve documentation - sysfs entry reset takes bus number as an argument
Documentation/ABI/testing/sysfs-bus-cdx | 8 ++++---- drivers/cdx/cdx.c | 26 +++++++++++++++++++++---- 2 files changed, 26 insertions(+), 8 deletions(-)
diff --git a/Documentation/ABI/testing/sysfs-bus-cdx b/Documentation/ABI/testing/sysfs-bus-cdx index c12bdaa4152a..c2c54abffed5 100644 --- a/Documentation/ABI/testing/sysfs-bus-cdx +++ b/Documentation/ABI/testing/sysfs-bus-cdx @@ -45,10 +45,10 @@ What: /sys/bus/cdx/devices/.../reset Date: March 2023 Contact: nipun.gupta@amd.com Description: - Writing y/1/on to this file resets the CDX device. - On resetting the device, the corresponding driver is notified - twice, once before the device is being reset, and again after - the reset has been complete. + Writing y/1/on to this file resets the CDX device or all devices + on the bus. On resetting the device, the corresponding driver is + notified twice, once before the device is being reset, and again + after the reset has been complete. For example:: diff --git a/drivers/cdx/cdx.c b/drivers/cdx/cdx.c index 8eb484c37e97..e22a7138292e 100644 --- a/drivers/cdx/cdx.c +++ b/drivers/cdx/cdx.c @@ -110,6 +110,20 @@ int cdx_dev_reset(struct device *dev) } EXPORT_SYMBOL_GPL(cdx_dev_reset); +/** + * reset_cdx_device - Reset a CDX device + * @dev: CDX device + * @data: This is always passed as NULL, and is not used in this API, + * but is required here as the device_for_each_child() API expects + * the passed function to have this as an argument. + * + * Return: -errno on failure, 0 on success. + */ +static int reset_cdx_device(struct device *dev, void *data) +{ + return cdx_dev_reset(dev); +} + /** * cdx_unregister_device - Unregister a CDX device * @dev: CDX device @@ -343,6 +357,7 @@ static DEVICE_ATTR_WO(remove); static ssize_t reset_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { + struct cdx_device *cdx_dev = to_cdx_device(dev); bool val; int ret; @@ -352,11 +367,13 @@ static ssize_t reset_store(struct device *dev, struct device_attribute *attr, if (!val) return -EINVAL; - ret = cdx_dev_reset(dev); - if (ret) - return ret; + if (cdx_dev->is_bus) + /* Reset all the devices attached to cdx bus */ + ret = device_for_each_child(dev, NULL, reset_cdx_device); + else + ret = cdx_dev_reset(dev); - return count; + return ret < 0 ? ret : count; } static DEVICE_ATTR_WO(reset); @@ -461,6 +478,7 @@ static const struct attribute_group cdx_dev_group = { static struct attribute *cdx_bus_dev_attrs[] = { &dev_attr_enable.attr, + &dev_attr_reset.attr, NULL, }; -- 2.34.1
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