From 2e5f10e4f0a9649186d8a8c793822b2e0dae8373 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Wed, 30 Apr 2008 15:37:19 -0400 Subject: USB: create attributes before sending uevent This patch (as1087d) fixes a long-standing problem in usbcore: Device, interface, and endpoint attributes aren't added until _after_ the creation uevent has already been broadcast. Unfortunately there are a few attributes which cannot be created that early. The "descriptors" attribute is binary and so must be created separately. The power-management attributes can't be created until the dev/power/ group exists. And the interface string can vary from one altsetting to another, so it has to be created dynamically. Signed-off-by: Alan Stern Cc: Kay Sievers Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/sysfs.c | 137 +++++++++++++++++++++++++++++------------------ 1 file changed, 85 insertions(+), 52 deletions(-) (limited to 'drivers/usb/core/sysfs.c') diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c index 5b20a60de8ba..c783cb111847 100644 --- a/drivers/usb/core/sysfs.c +++ b/drivers/usb/core/sysfs.c @@ -538,6 +538,46 @@ static struct attribute_group dev_attr_grp = { .attrs = dev_attrs, }; +/* When modifying this list, be sure to modify dev_string_attrs_are_visible() + * accordingly. + */ +static struct attribute *dev_string_attrs[] = { + &dev_attr_manufacturer.attr, + &dev_attr_product.attr, + &dev_attr_serial.attr, + NULL +}; + +static mode_t dev_string_attrs_are_visible(struct kobject *kobj, + struct attribute *a, int n) +{ + struct usb_device *udev = to_usb_device( + container_of(kobj, struct device, kobj)); + + if (a == &dev_attr_manufacturer.attr) { + if (udev->manufacturer == NULL) + return 0; + } else if (a == &dev_attr_product.attr) { + if (udev->product == NULL) + return 0; + } else if (a == &dev_attr_serial.attr) { + if (udev->serial == NULL) + return 0; + } + return a->mode; +} + +static struct attribute_group dev_string_attr_grp = { + .attrs = dev_string_attrs, + .is_visible = dev_string_attrs_are_visible, +}; + +struct attribute_group *usb_device_groups[] = { + &dev_attr_grp, + &dev_string_attr_grp, + NULL +}; + /* Binary descriptors */ static ssize_t @@ -591,10 +631,9 @@ int usb_create_sysfs_dev_files(struct usb_device *udev) struct device *dev = &udev->dev; int retval; - retval = sysfs_create_group(&dev->kobj, &dev_attr_grp); - if (retval) - return retval; - + /* Unforunately these attributes cannot be created before + * the uevent is broadcast. + */ retval = device_create_bin_file(dev, &dev_bin_attr_descriptors); if (retval) goto error; @@ -607,21 +646,6 @@ int usb_create_sysfs_dev_files(struct usb_device *udev) if (retval) goto error; - if (udev->manufacturer) { - retval = device_create_file(dev, &dev_attr_manufacturer); - if (retval) - goto error; - } - if (udev->product) { - retval = device_create_file(dev, &dev_attr_product); - if (retval) - goto error; - } - if (udev->serial) { - retval = device_create_file(dev, &dev_attr_serial); - if (retval) - goto error; - } retval = usb_create_ep_files(dev, &udev->ep0, udev); if (retval) goto error; @@ -636,13 +660,9 @@ void usb_remove_sysfs_dev_files(struct usb_device *udev) struct device *dev = &udev->dev; usb_remove_ep_files(&udev->ep0); - device_remove_file(dev, &dev_attr_manufacturer); - device_remove_file(dev, &dev_attr_product); - device_remove_file(dev, &dev_attr_serial); remove_power_attributes(dev); remove_persist_attributes(dev); device_remove_bin_file(dev, &dev_bin_attr_descriptors); - sysfs_remove_group(&dev->kobj, &dev_attr_grp); } /* Interface Accociation Descriptor fields */ @@ -688,17 +708,15 @@ static ssize_t show_interface_string(struct device *dev, struct device_attribute *attr, char *buf) { struct usb_interface *intf; - struct usb_device *udev; - int len; + char *string; intf = to_usb_interface(dev); - udev = interface_to_usbdev(intf); - len = snprintf(buf, 256, "%s", intf->cur_altsetting->string); - if (len < 0) + string = intf->cur_altsetting->string; + barrier(); /* The altsetting might change! */ + + if (!string) return 0; - buf[len] = '\n'; - buf[len+1] = 0; - return len+1; + return sprintf(buf, "%s\n", string); } static DEVICE_ATTR(interface, S_IRUGO, show_interface_string, NULL); @@ -727,18 +745,6 @@ static ssize_t show_modalias(struct device *dev, } static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL); -static struct attribute *intf_assoc_attrs[] = { - &dev_attr_iad_bFirstInterface.attr, - &dev_attr_iad_bInterfaceCount.attr, - &dev_attr_iad_bFunctionClass.attr, - &dev_attr_iad_bFunctionSubClass.attr, - &dev_attr_iad_bFunctionProtocol.attr, - NULL, -}; -static struct attribute_group intf_assoc_attr_grp = { - .attrs = intf_assoc_attrs, -}; - static struct attribute *intf_attrs[] = { &dev_attr_bInterfaceNumber.attr, &dev_attr_bAlternateSetting.attr, @@ -753,6 +759,37 @@ static struct attribute_group intf_attr_grp = { .attrs = intf_attrs, }; +static struct attribute *intf_assoc_attrs[] = { + &dev_attr_iad_bFirstInterface.attr, + &dev_attr_iad_bInterfaceCount.attr, + &dev_attr_iad_bFunctionClass.attr, + &dev_attr_iad_bFunctionSubClass.attr, + &dev_attr_iad_bFunctionProtocol.attr, + NULL, +}; + +static mode_t intf_assoc_attrs_are_visible(struct kobject *kobj, + struct attribute *a, int n) +{ + struct usb_interface *intf = to_usb_interface( + container_of(kobj, struct device, kobj)); + + if (intf->intf_assoc == NULL) + return 0; + return a->mode; +} + +static struct attribute_group intf_assoc_attr_grp = { + .attrs = intf_assoc_attrs, + .is_visible = intf_assoc_attrs_are_visible, +}; + +struct attribute_group *usb_interface_groups[] = { + &intf_attr_grp, + &intf_assoc_attr_grp, + NULL +}; + static inline void usb_create_intf_ep_files(struct usb_interface *intf, struct usb_device *udev) { @@ -777,23 +814,21 @@ static inline void usb_remove_intf_ep_files(struct usb_interface *intf) int usb_create_sysfs_intf_files(struct usb_interface *intf) { - struct device *dev = &intf->dev; struct usb_device *udev = interface_to_usbdev(intf); struct usb_host_interface *alt = intf->cur_altsetting; int retval; if (intf->sysfs_files_created) return 0; - retval = sysfs_create_group(&dev->kobj, &intf_attr_grp); - if (retval) - return retval; + /* The interface string may be present in some altsettings + * and missing in others. Hence its attribute cannot be created + * before the uevent is broadcast. + */ if (alt->string == NULL) alt->string = usb_cache_string(udev, alt->desc.iInterface); if (alt->string) - retval = device_create_file(dev, &dev_attr_interface); - if (intf->intf_assoc) - retval = sysfs_create_group(&dev->kobj, &intf_assoc_attr_grp); + retval = device_create_file(&intf->dev, &dev_attr_interface); usb_create_intf_ep_files(intf, udev); intf->sysfs_files_created = 1; return 0; @@ -807,7 +842,5 @@ void usb_remove_sysfs_intf_files(struct usb_interface *intf) return; usb_remove_intf_ep_files(intf); device_remove_file(dev, &dev_attr_interface); - sysfs_remove_group(&dev->kobj, &intf_attr_grp); - sysfs_remove_group(&intf->dev.kobj, &intf_assoc_attr_grp); intf->sysfs_files_created = 0; } -- cgit v1.2.3