<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - Intel GeminiLake corruption at top of screen caused by fbc" href="https://bugs.freedesktop.org/show_bug.cgi?id=108085#c40">Comment # 40</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - Intel GeminiLake corruption at top of screen caused by fbc" href="https://bugs.freedesktop.org/show_bug.cgi?id=108085">bug 108085</a> from <a class="email" href="mailto:james.ausmus@intel.com" title="James Ausmus <james.ausmus@intel.com>"> James Ausmus</a> <pre>Hi Geraud- If $ cat /sys/module/i915/parameters/enable_fbc gives you a 1, that means that the module parameter is set to allow FBC. However, this doesn't necessarily mean that FBC is active/enabled. To check this, you'll need to either look at a file in debugfs, or boot with the "drm.debug=0xe" parameter and check your kernel logs. To check the file in debugfs, do: $ mount | grep debugfs if this doesn't return results, then debugfs isn't mounted (or may not even be enabled in your kernel config) - you can choose to enable/mount debugfs if you choose - see <a href="https://www.kernel.org/doc/Documentation/filesystems/debugfs.txt">https://www.kernel.org/doc/Documentation/filesystems/debugfs.txt</a> for some examples. If the mount command *did* return results, it probably looked something like: $ mount | grep debugfs debugfs on /sys/kernel/debug type debugfs (rw,nosuid,nodev,noexec,relatime) Then you can do: $ cat /sys/kernel/debug/dri/0/i915_fbc_status which will give you the "this moment right now" status of FBC. Alternatively, if you wan't to check via the kernel log, boot with the "drm.debug=0xe" kernel parameter, and then do: $ dmesg | grep -i fbc Which should give at least a few lines about FBC enabling and FBC status.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> <li>You are the assignee for the bug.</li> <li>You are on the CC list for the bug.</li> </ul> </body> </html>