<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_REOPENED " title="REOPENED - [HSW] X server hang when toggling fullscreen in media player" href="https://bugs.freedesktop.org/show_bug.cgi?id=100162#c14">Comment # 14</a> on <a class="bz_bug_link bz_status_REOPENED " title="REOPENED - [HSW] X server hang when toggling fullscreen in media player" href="https://bugs.freedesktop.org/show_bug.cgi?id=100162">bug 100162</a> from <a class="email" href="mailto:thomas.lindroth@gmail.com" title="Thomas Lindroth <thomas.lindroth@gmail.com>"> Thomas Lindroth</a> <pre>I tried setting intel_iommu=on,igfx_off but as expected this broke IOMMU in kvm. I don't know why that happens. As I understand it igfx_off should only disable the IOMMU dedicated to the igpu without changing anything else. With igfx_off I got errors like these when trying to start a VM with kvm: DMAR: DRHD: handling fault status reg 3 DMAR: DMAR:[DMA Read] Request device [04:00.1] fault addr 1eac00000 DMAR:[fault reason 12] non-zero reserved fields in PTE device [04:00.1] is one of the devices I assign to the VM. "non-zero reserved fields in PTE" is an odd error. It makes me think there is some corruption of the IOMMU pagetables caused by the igfx_off option. While I was testing igfx_off I got lucky and did get a hang. The hang looked the same as all my other hangs. "WARNING: CPU: 0 PID: 3133 at /usr/src/linux-4.4.89/drivers/gpu/drm/i915/inte l_display.c:3965 intel_crtc_wait_for_pending_flips+0x1dd/0x230()". Since the hangs happen even with igfx_off I guess the problem is not IOMMU related.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are on the CC list for the bug.</li> <li>You are the QA Contact for the bug.</li> <li>You are the assignee for the bug.</li> </ul> </body> </html>