From: Emil Velikov <emil.velikov@xxxxxxxxxxxxx>
Introduce a helper which gets the real sysfs path for the given pci
device.
In other words, instead opening the /sys/dev/char/*/device symlink, we
opt for the actual /sys/devices/pci*/*/
It folds three (nearly identical) snprintf's and paves the way of adding
extra devices (see next patch) a piece of pie.
Signed-off-by: Emil Velikov <emil.velikov@xxxxxxxxxxxxx>
---
xf86drm.c | 62 ++++++++++++++++++++++++++++++++++++++++++++-----------
1 file changed, 50 insertions(+), 12 deletions(-)
diff --git a/xf86drm.c b/xf86drm.c
index d4810740..8ccd528f 100644
--- a/xf86drm.c
+++ b/xf86drm.c
@@ -2992,16 +2992,37 @@ static int drmParseSubsystemType(int maj, int min)
#endif
}
+static char *
+get_real_pci_path(int maj, int min)
+{
+ char path[PATH_MAX + 1];
+ char *real_path = malloc(PATH_MAX);
+
+ if (!real_path)
+ return NULL;
+
+ snprintf(path, sizeof(path), "/sys/dev/char/%d:%d/device", maj, min);
+ if (!realpath(path, real_path)) {
+ free(real_path);
+ return NULL;
+ }
+
+ return real_path;
+}
+
static int drmParsePciBusInfo(int maj, int min, drmPciBusInfoPtr info)
{
#ifdef __linux__
unsigned int domain, bus, dev, func;
- char path[PATH_MAX + 1], *value;
+ char *real_path, *value;
int num;
- snprintf(path, sizeof(path), "/sys/dev/char/%d:%d/device", maj, min);
+ real_path = get_real_pci_path(maj, min);
+ if (!real_path)
+ return -ENOENT;
- value = sysfs_uevent_get(path, "PCI_SLOT_NAME");
+ value = sysfs_uevent_get(real_path, "PCI_SLOT_NAME");
+ free(real_path);
if (!value)
return -ENOENT;
@@ -3114,24 +3135,32 @@ static int parse_separate_sysfs_files(int maj, int min,
"subsystem_vendor",
"subsystem_device",
};
- char path[PATH_MAX + 1];
+ char path[PATH_MAX + 1], *real_path;
unsigned int data[ARRAY_SIZE(attrs)];
FILE *fp;
int ret;
+ real_path = get_real_pci_path(maj, min);
+ if (!real_path)
+ return -ENOENT;
+
for (unsigned i = ignore_revision ? 1 : 0; i < ARRAY_SIZE(attrs); i++) {
- snprintf(path, PATH_MAX, "/sys/dev/char/%d:%d/device/%s", maj, min,
- attrs[i]);
+ snprintf(path, PATH_MAX, "%s/%s", real_path, attrs[i]);
fp = fopen(path, "r");
- if (!fp)
+ if (!fp) {
+ free(real_path);
return -errno;
+ }
ret = fscanf(fp, "%x", &data[i]);
fclose(fp);
- if (ret != 1)
+ if (ret != 1) {
+ free(real_path);
return -errno;
+ }
}
+ free(real_path);
device->revision_id = ignore_revision ? 0xff : data[0] & 0xff;
device->vendor_id = data[1] & 0xffff;
@@ -3145,19 +3174,28 @@ static int parse_separate_sysfs_files(int maj, int min,
static int parse_config_sysfs_file(int maj, int min,
drmPciDeviceInfoPtr device)
{
- char path[PATH_MAX + 1];
+ char path[PATH_MAX + 1], *real_path;
unsigned char config[64];
int fd, ret;
- snprintf(path, PATH_MAX, "/sys/dev/char/%d:%d/device/config", maj, min);
+ real_path = get_real_pci_path(maj, min);
+ if (!real_path)
+ return -ENOENT;
+
+ snprintf(path, PATH_MAX, "%s/config", real_path);
fd = open(path, O_RDONLY);
- if (fd < 0)
+ if (fd < 0) {
+ free(real_path);
return -errno;
+ }
ret = read(fd, config, sizeof(config));
close(fd);
- if (ret < 0)
+ if (ret < 0) {
+ free(real_path);
return -errno;
+ }
+ free(real_path);
device->vendor_id = config[0] | (config[1] << 8);
device->device_id = config[2] | (config[3] << 8);
