From: Emil Velikov <emil.veli...@collabora.com> Parsing config sysfs file wakes up the device. The latter of which may be slow and isn't required to begin with.
Reading through config is/was required since the revision is not available by other means, although with a kernel patch in the way we can 'cheat' temporarily. That should be fine, since no open-source project has ever used the value. Cc: Michel Dänzer <michel.daenzer at amd.com> Cc: Mauro Santos <registo.mailling at gmail.com> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=98502 Signed-off-by: Emil Velikov <emil.velikov at collabora.com> --- Mauro can you apply this against libdrm and rebuild it. You do _not_ need to rebuild mesa afterwords. Thanks --- xf86drm.c | 50 +++++++++++++++++++++++++++++++++++--------------- 1 file changed, 35 insertions(+), 15 deletions(-) diff --git a/xf86drm.c b/xf86drm.c index 52add5e..5a5100c 100644 --- a/xf86drm.c +++ b/xf86drm.c @@ -2950,25 +2950,45 @@ static int drmParsePciDeviceInfo(const char *d_name, drmPciDeviceInfoPtr device) { #ifdef __linux__ +#define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0])) + static const char *attrs[] = { + "revision", /* XXX: make sure it's always first, see note below */ + "vendor", + "device", + "subsystem_vendor", + "subsystem_device", + }; char path[PATH_MAX + 1]; - unsigned char config[64]; - int fd, ret; + unsigned int data[ARRAY_SIZE(attrs)]; + FILE *fp; + int ret; - snprintf(path, PATH_MAX, "/sys/class/drm/%s/device/config", d_name); - fd = open(path, O_RDONLY); - if (fd < 0) - return -errno; + for (unsigned i = 0; i < ARRAY_SIZE(attrs); i++) { + snprintf(path, PATH_MAX, "/sys/class/drm/%s/device/%s", + d_name, attrs[i]); + fp = fopen(path, "r"); + if (!fp) { + /* Note: First we check the revision, since older kernels + * may not have it. Default to zero in such cases. */ + if (i == 0) { + data[i] = 0; + continue; + } + return -errno; + } - ret = read(fd, config, sizeof(config)); - close(fd); - if (ret < 0) - return -errno; + ret = fscanf(fp, "%x", &data[i]); + fclose(fp); + if (ret != 1) + return -errno; + + } - device->vendor_id = config[0] | (config[1] << 8); - device->device_id = config[2] | (config[3] << 8); - device->revision_id = config[8]; - device->subvendor_id = config[44] | (config[45] << 8); - device->subdevice_id = config[46] | (config[47] << 8); + device->revision_id = data[0] & 0xff; + device->vendor_id = data[1] & 0xffff; + device->device_id = data[2] & 0xffff; + device->subvendor_id = data[3] & 0xffff; + device->subdevice_id = data[4] & 0xffff; return 0; #else -- 2.10.0
