#include #include #include #include #include #include #include #include #include #include static int set_immutable(const char *path, int immutable) { unsigned int flags; int fd; int rc; int error; fd = open(path, O_RDONLY); if (fd < 0) return fd; rc = ioctl(fd, FS_IOC_GETFLAGS, &flags); if (rc < 0) { error = errno; close(fd); errno = error; return rc; } if (immutable) flags |= FS_IMMUTABLE_FL; else flags &= ~FS_IMMUTABLE_FL; rc = ioctl(fd, FS_IOC_SETFLAGS, &flags); error = errno; close(fd); errno = error; return rc; } static int get_immutable(const char *path) { unsigned int flags; int fd; int rc; int error; fd = open(path, O_RDONLY); if (fd < 0) return fd; rc = ioctl(fd, FS_IOC_GETFLAGS, &flags); if (rc < 0) { error = errno; close(fd); errno = error; return rc; } close(fd); if (flags & FS_IMMUTABLE_FL) return 1; return 0; } int main(int argc, char **argv) { const char *path; char buf[5]; int fd, rc; if (argc < 2) { fprintf(stderr, "usage: %s \n", argv[0]); return EXIT_FAILURE; } path = argv[1]; /* attributes: EFI_VARIABLE_NON_VOLATILE | * EFI_VARIABLE_BOOTSERVICE_ACCESS | * EFI_VARIABLE_RUNTIME_ACCESS */ *(uint32_t *)buf = 0x7; buf[4] = 0; /* create a test variable */ fd = open(path, O_WRONLY | O_CREAT, 0600); if (fd < 0) { perror("open(O_WRONLY)"); return EXIT_FAILURE; } rc = write(fd, buf, sizeof(buf)); if (rc != sizeof(buf)) { perror("write"); return EXIT_FAILURE; } close(fd); rc = get_immutable(path); if (rc < 0) { perror("ioctl(FS_IOC_GETFLAGS)"); return EXIT_FAILURE; } else if (rc) { rc = set_immutable(path, 0); if (rc < 0) { perror("ioctl(FS_IOC_SETFLAGS)"); return EXIT_FAILURE; } } fd = open(path, O_RDONLY); if (fd < 0) { perror("open"); return EXIT_FAILURE; } if (unlink(path) < 0) { perror("unlink"); return EXIT_FAILURE; } rc = read(fd, buf, sizeof(buf)); if (rc > 0) { fprintf(stderr, "reading from an unlinked variable " "shouldn't be possible\n"); return EXIT_FAILURE; } return EXIT_SUCCESS; } s-private-remove&id=e6e7b48b295afa5a5ab440de0a94d9ad8b3ce2d0'>diff

path: root/sound/soc/pxa/zylonite.c

diff options

author	Daniel Vetter <daniel.vetter@ffwll.ch>	2017-01-12 17:15:56 +0100
committer	Daniel Vetter <daniel.vetter@ffwll.ch>	2017-01-30 10:17:32 +0100
commit	e6e7b48b295afa5a5ab440de0a94d9ad8b3ce2d0 (patch)
tree	77cadb6d8aad1b52c34e4afa8c9deef603bbe2ed /sound/soc/pxa/zylonite.c
parent	4e5b54f127426c82dc2816340c26d951a5bb3429 (diff)

drm: Don't race connector registration

I was under the misconception that the sysfs dev stuff can be fully set up, and then registered all in one step with device_add. That's true for properties and property groups, but not for parents and child devices. Those must be fully registered before you can register a child. Add a bit of tracking to make sure that asynchronous mst connector hotplugging gets this right. For consistency we rely upon the implicit barriers of the connector->mutex, which is taken anyway, to ensure that at least either the connector or device registration call will work out. Mildly tested since I can't reliably reproduce this on my mst box here. Reported-by: Dave Hansen <dave.hansen@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Acked-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/1484237756-2720-1-git-send-email-daniel.vetter@ffwll.ch

Diffstat (limited to 'sound/soc/pxa/zylonite.c')