Re: [PATCH] bus: mhi: pci_generic: Apply no-op for wake using inband wake support flag

[Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>]

On Thu, Jun 17, 2021 at 11:23:53AM -0700, Bhaumik Bhatt wrote:
> Devices such as SDX24 do not have the provision for inband wake
> doorbell in the form of channel 127. Newer devices such as SDX55
> or SDX65 have it by default. Ensure the functionality is used
> based on this such that device wake stays held when a client
> driver uses mhi_device_get() API or the equivalent debugfs entry.
> 
> Fixes: e3e5e6508fc1 ("bus: mhi: pci_generic: No-Op for device_wake operations")
> Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
> ---
>  drivers/bus/mhi/pci_generic.c | 26 ++++++++++++++++++--------
>  1 file changed, 18 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/bus/mhi/pci_generic.c b/drivers/bus/mhi/pci_generic.c
> index d84b743..31360a2 100644
> --- a/drivers/bus/mhi/pci_generic.c
> +++ b/drivers/bus/mhi/pci_generic.c
> @@ -32,6 +32,7 @@
>   * @edl: emergency download mode firmware path (if any)
>   * @bar_num: PCI base address register to use for MHI MMIO register space
>   * @dma_data_width: DMA transfer word size (32 or 64 bits)
> + * @no_inband_wake: Devices without inband wake support (such as sdx24)

I'd rather like this field to be "inband_wake" and set to false/true
based on the capability of the devices. Rest looks good.

Thanks,
Mani

>   */
>  struct mhi_pci_dev_info {
>  	const struct mhi_controller_config *config;
> @@ -40,6 +41,7 @@ struct mhi_pci_dev_info {
>  	const char *edl;
>  	unsigned int bar_num;
>  	unsigned int dma_data_width;
> +	bool no_inband_wake;
>  };
>  
>  #define MHI_CHANNEL_CONFIG_UL(ch_num, ch_name, el_count, ev_ring) \
> @@ -242,7 +244,8 @@ static const struct mhi_pci_dev_info mhi_qcom_sdx65_info = {
>  	.edl = "qcom/sdx65m/edl.mbn",
>  	.config = &modem_qcom_v1_mhiv_config,
>  	.bar_num = MHI_PCI_DEFAULT_BAR_NUM,
> -	.dma_data_width = 32
> +	.dma_data_width = 32,
> +	.no_inband_wake = false
>  };
>  
>  static const struct mhi_pci_dev_info mhi_qcom_sdx55_info = {
> @@ -251,7 +254,8 @@ static const struct mhi_pci_dev_info mhi_qcom_sdx55_info = {
>  	.edl = "qcom/sdx55m/edl.mbn",
>  	.config = &modem_qcom_v1_mhiv_config,
>  	.bar_num = MHI_PCI_DEFAULT_BAR_NUM,
> -	.dma_data_width = 32
> +	.dma_data_width = 32,
> +	.no_inband_wake = false
>  };
>  
>  static const struct mhi_pci_dev_info mhi_qcom_sdx24_info = {
> @@ -259,7 +263,8 @@ static const struct mhi_pci_dev_info mhi_qcom_sdx24_info = {
>  	.edl = "qcom/prog_firehose_sdx24.mbn",
>  	.config = &modem_qcom_v1_mhiv_config,
>  	.bar_num = MHI_PCI_DEFAULT_BAR_NUM,
> -	.dma_data_width = 32
> +	.dma_data_width = 32,
> +	.no_inband_wake = true
>  };
>  
>  static const struct mhi_channel_config mhi_quectel_em1xx_channels[] = {
> @@ -301,7 +306,8 @@ static const struct mhi_pci_dev_info mhi_quectel_em1xx_info = {
>  	.edl = "qcom/prog_firehose_sdx24.mbn",
>  	.config = &modem_quectel_em1xx_config,
>  	.bar_num = MHI_PCI_DEFAULT_BAR_NUM,
> -	.dma_data_width = 32
> +	.dma_data_width = 32,
> +	.no_inband_wake = true
>  };
>  
>  static const struct mhi_channel_config mhi_foxconn_sdx55_channels[] = {
> @@ -339,7 +345,8 @@ static const struct mhi_pci_dev_info mhi_foxconn_sdx55_info = {
>  	.edl = "qcom/sdx55m/edl.mbn",
>  	.config = &modem_foxconn_sdx55_config,
>  	.bar_num = MHI_PCI_DEFAULT_BAR_NUM,
> -	.dma_data_width = 32
> +	.dma_data_width = 32,
> +	.no_inband_wake = false
>  };
>  
>  static const struct pci_device_id mhi_pci_id_table[] = {
> @@ -640,9 +647,12 @@ static int mhi_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>  	mhi_cntrl->status_cb = mhi_pci_status_cb;
>  	mhi_cntrl->runtime_get = mhi_pci_runtime_get;
>  	mhi_cntrl->runtime_put = mhi_pci_runtime_put;
> -	mhi_cntrl->wake_get = mhi_pci_wake_get_nop;
> -	mhi_cntrl->wake_put = mhi_pci_wake_put_nop;
> -	mhi_cntrl->wake_toggle = mhi_pci_wake_toggle_nop;
> +
> +	if (info->no_inband_wake) {
> +		mhi_cntrl->wake_get = mhi_pci_wake_get_nop;
> +		mhi_cntrl->wake_put = mhi_pci_wake_put_nop;
> +		mhi_cntrl->wake_toggle = mhi_pci_wake_toggle_nop;
> +	}
>  
>  	err = mhi_pci_claim(mhi_cntrl, info->bar_num, DMA_BIT_MASK(info->dma_data_width));
>  	if (err)
> -- 
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>