xf86drm.c: Use integer logarithm.

log() is affected by FP control word and can provide inaccurate result.

Fixes Killer Instinct under Wine not being able to find AMD vulkan
device.

Reviewed-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Paul Gofman <pgofman@codeweavers.com>
main
Paul Gofman 2020-10-26 16:11:20 +03:00 committed by Dave Airlie
parent 3e9f211303
commit ad7cf9d75c
1 changed files with 17 additions and 1 deletions

View File

@ -124,6 +124,22 @@ static drmServerInfoPtr drm_server_info;
static bool drmNodeIsDRM(int maj, int min);
static char *drmGetMinorNameForFD(int fd, int type);
static unsigned log2_int(unsigned x)
{
unsigned l;
if (x < 2) {
return 0;
}
for (l = 2; ; l++) {
if ((unsigned)(1 << l) > x) {
return l - 1;
}
}
return 0;
}
drm_public void drmSetServerInfo(drmServerInfoPtr info)
{
drm_server_info = info;
@ -4001,7 +4017,7 @@ static void drmFoldDuplicatedDevices(drmDevicePtr local_devices[], int count)
for (j = i + 1; j < count; j++) {
if (drmDevicesEqual(local_devices[i], local_devices[j])) {
local_devices[i]->available_nodes |= local_devices[j]->available_nodes;
node_type = log2(local_devices[j]->available_nodes);
node_type = log2_int(local_devices[j]->available_nodes);
memcpy(local_devices[i]->nodes[node_type],
local_devices[j]->nodes[node_type], drmGetMaxNodeName());
drmFreeDevice(&local_devices[j]);