# --- T2-COPYRIGHT-BEGIN ---
# t2/package/*/libpciaccess/hotfix-pci_sys-refcnt.patch
# Copyright (C) 2025 The T2 SDE Project
# SPDX-License-Identifier: GPL-2.0 or patched project license
# --- T2-COPYRIGHT-END ---

Patch for libpciaccess 0.13.2 to "reference count" init/cleanup calls.

Fix X crashing w/ at least the legacy i915 driver:

Thread 1 "X" received signal SIGSEGV, Segmentation fault.
0x0000148f0e14c369 in pci_device_vgaarb_set_target (dev=0x0) at ../src/common_vgaarb.c:235
235             dev = pci_sys->vga_default_dev;
(gdb) bt
#0  0x0000148f0e14c369 in pci_device_vgaarb_set_target (dev=0x0) at ../src/common_vgaarb.c:235
#1  0x0000560899901ba7 in xf86VGAarbiterLock (pScrn=pScrn@entry=0x5608a94018d0) at xf86VGAarbiter.c:92
#2  0x00005608998e86b8 in xf86DPMS (pScreen=<optimized out>, level=0) at xf86DPMS.c:56
#3  0x0000560899955eae in DPMSSet (client=<optimized out>, level=level@entry=0) at dpms.c:106
#4  0x0000560899955f1a in DPMSCloseDownExtension (e=<optimized out>) at dpms.c:429
#5  0x00005608998bbe5e in CloseDownExtensions () at extension.c:201
#6  0x00005608998ac28e in dix_main (argc=1, argv=0x7ffc9f329d98, envp=<optimized out>) at main.c:285
#7  0x0000560899895cdf in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at stubmain.c:34

--- a/src/common_init.c	2014-09-14 03:17:38.628195344 +0400
+++ b/src/common_init.c	2014-09-14 03:19:31.402246351 +0400
@@ -36,6 +36,7 @@
 #include "pciaccess_private.h"
 
 _pci_hidden struct pci_system * pci_sys;
+static int pci_sys_refcnt = 0;
 
 /**
  * Initialize the PCI subsystem for access.
@@ -52,6 +53,11 @@ pci_system_init( void )
 {
     int err = ENOSYS;
 
+    if ( pci_sys_refcnt > 0 ) {
+       pci_sys_refcnt++;
+       return 0;
+    }
+
 #ifdef __linux__
     err = pci_system_linux_sysfs_create();
 #elif defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__DragonFly__)
@@ -66,6 +72,10 @@ pci_system_init( void )
     err = pci_system_x86_create();
 #endif
 
+    if ( pci_sys ) {
+	pci_sys_refcnt = 1;
+    }
+
     return err;
 }
 
@@ -91,6 +101,9 @@ pci_system_cleanup( void )
 
     if ( pci_sys == NULL ) {
 	return;
+    } else if ( pci_sys_refcnt > 1 ) {
+	pci_sys_refcnt--;
+	return;
     }
 
     pci_io_cleanup();
@@ -123,4 +136,5 @@ pci_system_cleanup( void )
 
     free( pci_sys );
     pci_sys = NULL;
+    pci_sys_refcnt = 0;
 }