From dac056aa301def4d45ae63636b4b9c286bac8fa1 Mon Sep 17 00:00:00 2001 From: "greg@kroah.com" Date: Sat, 20 Dec 2003 01:05:13 -0800 Subject: [PATCH] [PATCH] try to wait until the proper device file shows up in sysfs. this still isn't working correctly for partitions, so don't think this is the final version... --- namedev.c | 159 +++++++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 147 insertions(+), 12 deletions(-) diff --git a/namedev.c b/namedev.c index 58986e25..30c276ae 100644 --- a/namedev.c +++ b/namedev.c @@ -30,6 +30,7 @@ #include #include #include +#include #include "list.h" #include "udev.h" @@ -284,6 +285,55 @@ static void apply_format(struct udevice *udev, unsigned char *string) } } +static struct bus_file { + char *bus; + char *file; +} bus_files[] = { + { .bus = "scsi", .file = "vendor" }, + { .bus = "usb", .file = "idVendor" }, + {} +}; + +#define SECONDS_TO_WAIT_FOR_FILE 10 +static void wait_for_device_to_initialize(struct sysfs_device *sysfs_device) +{ + /* sleep until we see the file for this specific bus type show up this + * is needed because we can easily out-run the kernel in looking for + * these files before the paticular subsystem has created them in the + * sysfs tree properly. + * + * And people thought that the /sbin/hotplug event system was going to + * be slow, poo on you for arguing that before even testing it... + */ + struct bus_file *b = &bus_files[0]; + struct sysfs_attribute *tmpattr; + int loop; + + while (1) { + if (b->bus == NULL) + break; + if (strcmp(sysfs_device->bus, b->bus) == 0) { + tmpattr = NULL; + loop = SECONDS_TO_WAIT_FOR_FILE; + while (loop--) { + dbg("looking for file '%s' on bus '%s'", b->file, b->bus); + tmpattr = sysfs_get_device_attr(sysfs_device, b->file); + if (tmpattr) { + /* found it! */ + goto exit; + } + /* sleep to give the kernel a chance to create the file */ + sleep(1); + } + dbg("Timed out waiting for '%s' file, continuing on anyway...", b->file); + goto exit; + } + b++; + } + dbg("Did not find bus type '%s' on list of bus_id_files, contact greg@kroah.com", sysfs_device->bus); +exit: + return; /* here to prevent compiler warning... */ +} static int exec_callout(struct config_device *dev, char *value, int len) { @@ -580,19 +630,84 @@ static void do_kernelname(struct sysfs_class_device *class_dev, struct udevice * strfieldcpy(udev->name, class_dev->name); } -int namedev_name_device(struct sysfs_class_device *class_dev, struct udevice *udev) +static struct sysfs_device *get_sysfs_device(struct sysfs_class_device *class_dev) { - struct sysfs_device *sysfs_device = NULL; - struct sysfs_class_device *class_dev_parent = NULL; - int retval = 0; - struct perm_device *perm; + struct sysfs_device *sysfs_device; + struct sysfs_class_device *class_dev_parent; + int loop; + int retval; + char filename[SYSFS_PATH_MAX + 6]; + + /* FIXME!!! */ + /* This is needed here as we can easily out-race the placement of the + * device symlink by the kernel. The call to sleep(1); will be removed + * once libsysfs can be queried for sysfs_get_classdev_device() + * multiple times and have it return the proper information when the + * class device really shows up. For now, we live with the time + * delay... + */ +// sleep(1); + loop = 10; + while (loop--) { + struct stat buf; + + strcpy(filename, class_dev->path); + strcat(filename, "/device"); + dbg("looking for '%s'", filename); + retval = stat(filename, &buf); + if (!retval) + break; +#if 0 + /* bah, let's go backwards up a level to see if the device is there, + * as block partitions don't point to the physical device. Need to fix that + * up in the kernel... + */ + if (strcmp(class_dev->classname, SYSFS_BLOCK_NAME) == 0) { + if (isdigit(class_dev->path[strlen(class_dev->path)-1])) { + char *temp = strrchr(filename, '/'); + if (temp) { + *temp = 0x00; + temp = strrchr(filename, '/'); + if (temp) { + *temp = 0x00; + strcat(filename, "/device"); + dbg("looking for '%s'", filename); + retval = stat(filename, &buf); + if (!retval) + break; + } + } + } + } +#endif +// class_dev_parent = sysfs_get_classdev_parent(class_dev); +// if (class_dev_parent == NULL) { +// dbg("sysfs_get_classdev_parent for class device '%s' failed", class_dev->name); +// } else { +// strcpy(filename, class_dev_parent->path); +// strcat(filename, "/device"); +// dbg("looking for '%s'", filename); +// retval = stat(filename, &buf); +// if (!retval) +// break; +// } +// } +// } + /* sleep to give the kernel a chance to create the device file */ + sleep(1); + } +// retval = -ENODEV; - udev->mode = 0; +// sleep(1); + + loop = 1; /* FIXME put a real value in here for when everything is fixed... */ + while (loop--) { + /* find the sysfs_device for this class device */ + /* Wouldn't it really be nice if libsysfs could do this for us? */ + sysfs_device = sysfs_get_classdev_device(class_dev); + if (sysfs_device != NULL) + goto exit; - /* find the sysfs_device for this class device */ - /* Wouldn't it really be nice if libsysfs could do this for us? */ - sysfs_device = sysfs_get_classdev_device(class_dev); - if (sysfs_device == NULL) { /* bah, let's go backwards up a level to see if the device is there, * as block partitions don't point to the physical device. Need to fix that * up in the kernel... @@ -601,23 +716,43 @@ int namedev_name_device(struct sysfs_class_device *class_dev, struct udevice *ud dbg("looking at block device"); if (isdigit(class_dev->path[strlen(class_dev->path)-1])) { dbg("really is a partition"); - class_dev_parent = sysfs_get_classdev_parent - (class_dev); + class_dev_parent = sysfs_get_classdev_parent(class_dev); if (class_dev_parent == NULL) { dbg("sysfs_get_classdev_parent for class device '%s' failed", class_dev->name); } else { dbg("class_dev_parent->name='%s'", class_dev_parent->name); sysfs_device = sysfs_get_classdev_device(class_dev_parent); + if (sysfs_device != NULL) + goto exit; } } } + /* sleep to give the kernel a chance to create the link */ + /* sleep(1); */ + } +// dbg("Timed out waiting for device symlink, continuing on anyway..."); +exit: + return sysfs_device; +} + +int namedev_name_device(struct sysfs_class_device *class_dev, struct udevice *udev) +{ + struct sysfs_device *sysfs_device = NULL; + struct sysfs_class_device *class_dev_parent = NULL; + int retval = 0; + struct perm_device *perm; + + udev->mode = 0; + /* find the sysfs_device associated with this class device */ + sysfs_device = get_sysfs_device(class_dev); if (sysfs_device) { dbg("sysfs_device->path='%s'", sysfs_device->path); dbg("sysfs_device->bus_id='%s'", sysfs_device->bus_id); dbg("sysfs_device->bus='%s'", sysfs_device->bus); strfieldcpy(udev->bus_id, sysfs_device->bus_id); + wait_for_device_to_initialize(sysfs_device); } else { dbg("class_dev->name = '%s'", class_dev->name); } -- 2.39.5