On Mon, Jan 04, 2021 at 06:11:28PM +0800, Carl Huang wrote:
> If controller 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@xxxxxxxxxxxxxx>
> Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
Applied to mhi-next!
Thanks,
Mani
> ---
> v3:
> - replace "client driver" with "controller driver"
> - add Reviewed-by: Manivannan Sadhasivam
>
> v2:
> - document irq_flags added to mhi_controller
>
> drivers/bus/mhi/core/init.c | 9 +++++++--
> include/linux/mhi.h | 2 ++
> 2 files changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
> index 381fdea..37903a8 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 controller driver has set irq_flags, use it */
> + if (mhi_cntrl->irq_flags)
> + irq_flags = mhi_cntrl->irq_flags;
> +
> /* 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 cb7cd54..77f1e3f 100644
> --- a/include/linux/mhi.h
> +++ b/include/linux/mhi.h
> @@ -351,6 +351,7 @@ struct mhi_controller_config {
> * @fbc_download: MHI host needs to do complete image transfer (optional)
> * @pre_init: MHI host needs to do pre-initialization before power up
> * @wake_set: Device wakeup set flag
> + * @irq_flags: irq flags passed to request_irq (optional)
> *
> * Fields marked as (required) need to be populated by the controller driver
> * before calling mhi_register_controller(). For the fields marked as (optional)
> @@ -440,6 +441,7 @@ struct mhi_controller {
> bool fbc_download;
> bool pre_init;
> bool wake_set;
> + unsigned long irq_flags;
> };
>
> /**
> --
> 2.7.4
>
