Re: [PATCH 2/2] hid: intel-ish-hid: ipc: Address EHL Sx resume issues

[Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>]

On Wed, 2020-12-16 at 14:36 +0800, Zhang Lixu wrote:
> When OOB is disabled, FW will be power gated when system is in
> S3/S4/S5
> which is the same behavior with legacy ISH FW.
> When OOB is enabled, FW will always power on which is totally
> different
> comparing to legacy ISH FW.
> 
> So NO_D3 flag is not enough to check FW's status after resume.
> Here we can use IPC FW status register to check host link status.
> If it is false, it means FW get reset after power gated, need go
> through
> the whole initialization flow; If it is true, it means FW is alive,
> just
> set host ready bit to let fw know host is up.
> 
> Co-developed-by: Wei Jiang <wei.w.jiang@intel.com>
> Signed-off-by: Wei Jiang <wei.w.jiang@intel.com>
> Signed-off-by: Even Xu <even.xu@intel.com>
> Signed-off-by: Zhang Lixu <lixu.zhang@intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

> ---
>  drivers/hid/intel-ish-hid/ipc/hw-ish.h  |  1 +
>  drivers/hid/intel-ish-hid/ipc/ipc.c     | 27
> +++++++++++++++++++++++++
>  drivers/hid/intel-ish-hid/ipc/pci-ish.c |  6 +++++-
>  3 files changed, 33 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/hid/intel-ish-hid/ipc/hw-ish.h
> b/drivers/hid/intel-ish-hid/ipc/hw-ish.h
> index 1fb294ca463e..111ad259ba74 100644
> --- a/drivers/hid/intel-ish-hid/ipc/hw-ish.h
> +++ b/drivers/hid/intel-ish-hid/ipc/hw-ish.h
> @@ -81,5 +81,6 @@ struct ishtp_device *ish_dev_init(struct pci_dev
> *pdev);
>  int ish_hw_start(struct ishtp_device *dev);
>  void ish_device_disable(struct ishtp_device *dev);
>  int ish_disable_dma(struct ishtp_device *dev);
> +void ish_set_host_ready(struct ishtp_device *dev);
>  
>  #endif /* _ISHTP_HW_ISH_H_ */
> diff --git a/drivers/hid/intel-ish-hid/ipc/ipc.c b/drivers/hid/intel-
> ish-hid/ipc/ipc.c
> index a45ac7fa417b..47bbeb8b492b 100644
> --- a/drivers/hid/intel-ish-hid/ipc/ipc.c
> +++ b/drivers/hid/intel-ish-hid/ipc/ipc.c
> @@ -193,6 +193,33 @@ static void ish_clr_host_rdy(struct ishtp_device
> *dev)
>         ish_reg_write(dev, IPC_REG_HOST_COMM, host_status);
>  }
>  
> +static bool ish_chk_host_rdy(struct ishtp_device *dev)
> +{
> +       uint32_t host_status = ish_reg_read(dev, IPC_REG_HOST_COMM);
> +
> +       return (host_status & IPC_HOSTCOMM_READY_BIT);
> +}
> +
> +/**
> + * ish_set_host_ready() - reconfig ipc host registers
> + * @dev: ishtp device pointer
> + *
> + * Set host to ready state
> + * This API is called in some case:
> + *    fw is still on, but ipc is powered down.
> + *    such as OOB case.
> + *
> + * Return: 0 for success else error fault code
> + */
> +void ish_set_host_ready(struct ishtp_device *dev)
> +{
> +       if (ish_chk_host_rdy(dev))
> +               return;
> +
> +       ish_set_host_rdy(dev);
> +       set_host_ready(dev);
> +}
> +
>  /**
>   * _ishtp_read_hdr() - Read message header
>   * @dev: ISHTP device pointer
> diff --git a/drivers/hid/intel-ish-hid/ipc/pci-ish.c
> b/drivers/hid/intel-ish-hid/ipc/pci-ish.c
> index c9c5488e44cb..8cb40696984a 100644
> --- a/drivers/hid/intel-ish-hid/ipc/pci-ish.c
> +++ b/drivers/hid/intel-ish-hid/ipc/pci-ish.c
> @@ -259,11 +259,15 @@ static void __maybe_unused
> ish_resume_handler(struct work_struct *work)
>  {
>         struct pci_dev *pdev = to_pci_dev(ish_resume_device);
>         struct ishtp_device *dev = pci_get_drvdata(pdev);
> +       uint32_t fwsts = dev->ops->get_fw_status(dev);
>         int ret;
>  
> -       if (ish_should_leave_d0i3(pdev) && !dev->suspend_flag) {
> +       if (ish_should_leave_d0i3(pdev) && !dev->suspend_flag
> +                       && IPC_IS_ISH_ILUP(fwsts)) {
>                 disable_irq_wake(pdev->irq);
>  
> +               ish_set_host_ready(dev);
> +
>                 ishtp_send_resume(dev);
>  
>                 /* Waiting to get resume response */