Messages in this thread | | | Subject | Re: [PATCH] mhi: use irq_flags if client driver configures it | From | Hemant Kumar <> | Date | Wed, 9 Dec 2020 10:34:22 -0800 |
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On 12/7/20 7:55 PM, Carl Huang wrote: > If client driver has specified the irq_flags, mhi uses this specified > irq_flags. Otherwise, mhi uses default irq_flags. > > The purpose of this change is to support one MSI vector for QCA6390. > MHI will use one same MSI vector too in this scenario. > > In case of one MSI vector, IRQ_NO_BALANCING is needed when irq handler > is requested. The reason is if irq migration happens, the msi_data may > change too. However, the msi_data is already programmed to QCA6390 > hardware during initialization phase. This msi_data inconsistence will > result in crash in kernel. > > Another issue is in case of one MSI vector, IRQF_NO_SUSPEND will trigger > WARNINGS because QCA6390 wants to disable the IRQ during the suspend. > > To avoid above two issues, QCA6390 driver specifies the irq_flags in case > of one MSI vector when mhi_register_controller is called. > > Signed-off-by: Carl Huang <cjhuang@codeaurora.org> > --- > drivers/bus/mhi/core/init.c | 9 +++++++-- > include/linux/mhi.h | 1 + > 2 files changed, 8 insertions(+), 2 deletions(-) > > diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c > index 0ffdebd..5f74e1e 100644 > --- a/drivers/bus/mhi/core/init.c > +++ b/drivers/bus/mhi/core/init.c > @@ -148,12 +148,17 @@ int mhi_init_irq_setup(struct mhi_controller *mhi_cntrl) > { > struct mhi_event *mhi_event = mhi_cntrl->mhi_event; > struct device *dev = &mhi_cntrl->mhi_dev->dev; > + unsigned long irq_flags = IRQF_SHARED | IRQF_NO_SUSPEND; > int i, ret; > > + /* if client driver has set irq_flags, use it */ > + if (mhi_cntrl->irq_flags) > + irq_flags = mhi_cntrl->irq_flags; Jeff if i remember correctly your use case also have one dedicated irq line for all the MSIs, just want to confirm if you are fine with this change ? i was wondering if any input check is required for irq_flags passed by controller, or responsibility is on controller for any undesired behavior. Like passing IRQF_SHARED and IRQF_ONESHOT when one irq line is shared among multiple MSIs. > + > /* Setup BHI_INTVEC IRQ */ > ret = request_threaded_irq(mhi_cntrl->irq[0], mhi_intvec_handler, > mhi_intvec_threaded_handler, > - IRQF_SHARED | IRQF_NO_SUSPEND, > + irq_flags, > "bhi", mhi_cntrl); > if (ret) > return ret; > @@ -171,7 +176,7 @@ int mhi_init_irq_setup(struct mhi_controller *mhi_cntrl) > > ret = request_irq(mhi_cntrl->irq[mhi_event->irq], > mhi_irq_handler, > - IRQF_SHARED | IRQF_NO_SUSPEND, > + irq_flags, > "mhi", mhi_event); > if (ret) { > dev_err(dev, "Error requesting irq:%d for ev:%d\n", > diff --git a/include/linux/mhi.h b/include/linux/mhi.h > index d4841e5..f039e58 100644 > --- a/include/linux/mhi.h > +++ b/include/linux/mhi.h > @@ -442,6 +442,7 @@ struct mhi_controller { > bool fbc_download; > bool pre_init; > bool wake_set; > + unsigned long irq_flags; > }; > > /** >
Thanks, Hemant
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