On Fri, Sep 18, 2020 at 07:02:32PM -0700, Bhaumik Bhatt wrote: > In some cases, the entry of device to RDDM execution environment > can occur after a significant amount of time has elapsed after the > SYS_ERROR state change event has arrived. This can result in scenarios > where users of the MHI bus are unaware of the error state of the
Who are all the users of MHI bus? Client drivers? > device. Hence, moving the MHI bus to a SYS_ERROR detected state will > prevent further client activity and wait for the RDDM entry. > > Signed-off-by: Bhaumik Bhatt <bbh...@codeaurora.org> > --- > drivers/bus/mhi/core/main.c | 24 ++++++++++++++++-------- > 1 file changed, 16 insertions(+), 8 deletions(-) > > diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c > index 2cff5dd..1c8e332 100644 > --- a/drivers/bus/mhi/core/main.c > +++ b/drivers/bus/mhi/core/main.c > @@ -376,6 +376,7 @@ irqreturn_t mhi_intvec_threaded_handler(int irq_number, > void *priv) > enum mhi_state state = MHI_STATE_MAX; > enum mhi_pm_state pm_state = 0; > enum mhi_ee_type ee = 0; > + bool handle_rddm = false; > > write_lock_irq(&mhi_cntrl->pm_lock); > if (!MHI_REG_ACCESS_VALID(mhi_cntrl->pm_state)) { > @@ -400,6 +401,17 @@ irqreturn_t mhi_intvec_threaded_handler(int irq_number, > void *priv) > /* If device supports RDDM don't bother processing SYS error */ > if (mhi_cntrl->rddm_image) { > if (mhi_cntrl->ee == MHI_EE_RDDM && mhi_cntrl->ee != ee) { > + /* prevent clients from queueing any more packets */ > + write_lock_irq(&mhi_cntrl->pm_lock); > + pm_state = mhi_tryset_pm_state(mhi_cntrl, > + MHI_PM_SYS_ERR_DETECT); The condition above already moves MHI to MHI_PM_SYS_ERR_DETECT if the state is MHI_STATE_SYS_ERR. Why are you doing it here again? Thanks, Mani > + if (pm_state == MHI_PM_SYS_ERR_DETECT) > + handle_rddm = true; > + write_unlock_irq(&mhi_cntrl->pm_lock); > + } > + > + if (handle_rddm) { > + dev_err(dev, "RDDM event occurred!\n"); > mhi_cntrl->status_cb(mhi_cntrl, MHI_CB_EE_RDDM); > wake_up_all(&mhi_cntrl->state_event); > } > @@ -733,19 +745,15 @@ int mhi_process_ctrl_ev_ring(struct mhi_controller > *mhi_cntrl, > break; > case MHI_STATE_SYS_ERR: > { > - enum mhi_pm_state new_state; > - > - /* skip SYS_ERROR handling if RDDM supported */ > - if (mhi_cntrl->ee == MHI_EE_RDDM || > - mhi_cntrl->rddm_image) > - break; > + enum mhi_pm_state state = MHI_PM_STATE_MAX; > > dev_dbg(dev, "System error detected\n"); > write_lock_irq(&mhi_cntrl->pm_lock); > - new_state = mhi_tryset_pm_state(mhi_cntrl, > + if (mhi_cntrl->ee != MHI_EE_RDDM) > + state = mhi_tryset_pm_state(mhi_cntrl, > MHI_PM_SYS_ERR_DETECT); > write_unlock_irq(&mhi_cntrl->pm_lock); > - if (new_state == MHI_PM_SYS_ERR_DETECT) > + if (state == MHI_PM_SYS_ERR_DETECT) > mhi_pm_sys_err_handler(mhi_cntrl); > break; > } > -- > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, > a Linux Foundation Collaborative Project >