On Thu, 2022-11-17 at 16:36 -0800, Alan Previn wrote: > A driver bug was recently discovered where the security firmware was > receiving internal HW signals indicating that session key expirations > had occurred. Architecturally, the firmware was expecting a response > from the GuC to acknowledge the event with the firmware side. > However the OS was in a suspended state and GuC had been reset. > Internal specifications actually required the driver to ensure > that all active sessions be properly cleaned up in such cases where > the system is suspended and the GuC potentially unable to respond. > > This patch adds the global teardown code in i915's suspend_prepare > code path. > > Signed-off-by: Alan Previn <[email protected]> > --- > --- a/drivers/gpu/drm/i915/pxp/intel_pxp_pm.c > +++ b/drivers/gpu/drm/i915/pxp/intel_pxp_pm.c > @@ -14,7 +14,7 @@ void intel_pxp_suspend_prepare(struct intel_pxp *pxp) > if (!intel_pxp_is_enabled(pxp)) > return; > > - pxp->arb_is_valid = false; > + intel_pxp_end(pxp); > > intel_pxp_invalidate(pxp); > } We discovered that depending on the runtime-pm behavior of the platform, this patch uncovers a hang on the mei component driver (when calling the mei-pxp's interface for sending messages to the firmware from within the suspend-prepare callstack).
As soon as that mei patch is fit for publication we shall either merge the patches into a single series or provide a link from here. ...alan
