On Mon, Oct 01, 2018 at 01:13:59PM -0700, Fubo Chen wrote:
On Tue, Sep 4, 2018 at 2:10 PM Peter Wu peter@lekensteyn.nl wrote:
"crtc->helper_private" is not initialized by the QXL driver and thus the "crtc_funcs->disable" call would crash (resulting in suspend failure). Fix this by converting the suspend/resume functions to use the drm_mode_config_helper_* helpers.
Tested system sleep with QEMU 3.0 using "echo mem > /sys/power/state". During suspend the following message is visible from QEMU:
spice/server/display-channel.c:2425:display_channel_validate_surface: canvas address is 0x7fd05da68308 for 0 (and is NULL) spice/server/display-channel.c:2426:display_channel_validate_surface: failed on 0This seems to be triggered by QXL_IO_NOTIFY_CMD after QXL_IO_DESTROY_PRIMARY_ASYNC, but aside from the warning things still seem to work (tested with both the GTK and -spice options).
Signed-off-by: Peter Wu peter@lekensteyn.nl
Is this a new issue or something that was introduced a long time ago? In the latter case, please consider adding a "Cc: stable@vger.kernel.org" tag to this patch.
I am not sure exactly when the issue was introduced, but the original code was added in v3.10-rc7-800-gd84300bf7934 while the new drm_mode_config_helper_suspend API was added in 4.16.
The intended call chain to initialize the private object seems to be: drm_crtc_helper_add <- qdev_crtc_init <- qxl_modeset_init <- qxl_pci_probe
If any error occurs along the callchain, then the helper_private pointer will remain NULL. Or if the crtc is obtained in a different way (not sure how).
Not sure if it is worth backporting, suspend/resume does not seem an important use case for VMs using QXL and the fix was not validated for older kernels.