Re: [PATCH] mhi: pci_generic: Fix inbound IPCR channel

[Bhaumik Bhatt <bbhatt@codeaurora.org>]

On 2021-07-08 02:32 AM, Loic Poulain wrote:
> The qrtr-mhi client driver assumes that inbound buffers are
> automatically allocated and queued by the MHI core, but this
> no happens for mhi pci devices since IPCR inbound channel is
> not flagged with auto_queue, causing unusable IPCR (qrtr)
> feature. Fix that.
> 
> Cc: stable@vger.kernel.org
> Fixes: 855a70c12021 ("bus: mhi: Add MHI PCI support for WWAN modems")
> Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
> ---
>  drivers/bus/mhi/pci_generic.c | 18 +++++++++++++++++-
>  1 file changed, 17 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/bus/mhi/pci_generic.c 
> b/drivers/bus/mhi/pci_generic.c
> index 8bc6149..6d2ddec 100644
> --- a/drivers/bus/mhi/pci_generic.c
> +++ b/drivers/bus/mhi/pci_generic.c
> @@ -75,6 +75,22 @@ struct mhi_pci_dev_info {
>  		.doorbell_mode_switch = false,		\
>  	}
> 
> +#define MHI_CHANNEL_CONFIG_DL_AUTOQUEUE(ch_num, ch_name, el_count, 
> ev_ring) \
> +	{						\
> +		.num = ch_num,				\
> +		.name = ch_name,			\
> +		.num_elements = el_count,		\
> +		.event_ring = ev_ring,			\
> +		.dir = DMA_FROM_DEVICE,			\
> +		.ee_mask = BIT(MHI_EE_AMSS),		\
> +		.pollcfg = 0,				\
> +		.doorbell = MHI_DB_BRST_DISABLE,	\
> +		.lpm_notify = false,			\
> +		.offload_channel = false,		\
> +		.doorbell_mode_switch = false,		\
> +		.auto_queue = true,			\
> +	}
> +
>  #define MHI_EVENT_CONFIG_CTRL(ev_ring, el_count) \
>  	{					\
>  		.num_elements = el_count,	\
> @@ -213,7 +229,7 @@ static const struct mhi_channel_config
> modem_qcom_v1_mhi_channels[] = {
>  	MHI_CHANNEL_CONFIG_UL(14, "QMI", 4, 0),
>  	MHI_CHANNEL_CONFIG_DL(15, "QMI", 4, 0),
>  	MHI_CHANNEL_CONFIG_UL(20, "IPCR", 8, 0),
> -	MHI_CHANNEL_CONFIG_DL(21, "IPCR", 8, 0),
> +	MHI_CHANNEL_CONFIG_DL_AUTOQUEUE(21, "IPCR", 8, 0),
>  	MHI_CHANNEL_CONFIG_UL_FP(34, "FIREHOSE", 32, 0),
>  	MHI_CHANNEL_CONFIG_DL_FP(35, "FIREHOSE", 32, 0),
>  	MHI_CHANNEL_CONFIG_HW_UL(100, "IP_HW0", 128, 2),
Why do we need to make this change when we have your new change being
picked up that does this from qrtr/mhi.c?

Thanks,
Bhaumik
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