From 56c21f877bda7b8c62c3d7925b070b5113d807f2 Mon Sep 17 00:00:00 2001 From: Emily Deng Date: Thu, 14 Feb 2019 15:53:38 +0800 Subject: [PATCH] libdrm: Fix issue about differrent domainID but same BDF For multiple GPUs which has the same BDF, but has different domain ID, the drmOpenByBusid will return the wrong fd when startx. The reproduce sequence as below: 1. Call drmOpenByBusid to open Card0, then will return the right fd0, and the fd0 is master privilege; 2. Call drmOpenByBusid to open Card1. In function drmOpenByBusid, it will open Card0 first, this time, the fd1 for opening Card0 is not master privilege, and will call drmSetInterfaceVersion to identify the domain ID feature, as the fd1 is not master privilege, then drmSetInterfaceVersion will fail, and then won't compare domain ID, then return the wrong fd for Card1. Solution: First loop search the best match fd about drm 1.4. Reviewed-by: Alex Deucher Signed-off-by: Emily Deng Signed-off-by: Alex Deucher --- xf86drm.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/xf86drm.c b/xf86drm.c index d006bb38..cbae3e28 100644 --- a/xf86drm.c +++ b/xf86drm.c @@ -586,8 +586,31 @@ static int drmOpenByBusid(const char *busid, int type) if (base < 0) return -1; + /* We need to try for 1.4 first for proper PCI domain support */ drmMsg("drmOpenByBusid: Searching for BusID %s\n", busid); for (i = base; i < base + DRM_MAX_MINOR; i++) { + fd = drmOpenMinor(i, 1, type); + drmMsg("drmOpenByBusid: drmOpenMinor returns %d\n", fd); + if (fd >= 0) { + sv.drm_di_major = 1; + sv.drm_di_minor = 4; + sv.drm_dd_major = -1; /* Don't care */ + sv.drm_dd_minor = -1; /* Don't care */ + if (!drmSetInterfaceVersion(fd, &sv)) { + buf = drmGetBusid(fd); + drmMsg("drmOpenByBusid: drmGetBusid reports %s\n", buf); + if (buf && drmMatchBusID(buf, busid, 1)) { + drmFreeBusid(buf); + return fd; + } + if (buf) + drmFreeBusid(buf); + } + close(fd); + } + } + + for (i = base; i < base + DRM_MAX_MINOR; i++) { fd = drmOpenMinor(i, 1, type); drmMsg("drmOpenByBusid: drmOpenMinor returns %d\n", fd); if (fd >= 0) {