Re: [PATCH v6 4/7] bus: mhi: Add QDU100 Sahara variant and firmware fallback

On Wed, Jul 01, 2026 at 04:07:38PM +0530, Kishore Batta wrote:
> The Sahara driver currently selects a firmware image table based on the
> attached device, but it does not recognize QDU100 devices that expose the
> protocol on the SAHARA MHI channel. As a result, the host cannot associate
> QDU100 devices with the correct firmware namespace during image transfer.
> 
> Extend the probe time variant selection to match the SAHARA MHI channel and
> associate it with the QDU100 firmware folder. Add a firmware lookup
> fallback for cases where an image does not have an explicit entry in the
> device's firmware table. This allows required images to be provisioned by
> the platform.
> 
> This change only affects devices matched on the SAHARA MHI channel and
> does not change behavior for existing AIC100 and AIC200 devices.
> 
> Signed-off-by: Kishore Batta <[email protected]>
> ---
>  drivers/bus/mhi/host/clients/sahara/sahara.c | 27 +++++++++++++++--
>  drivers/bus/mhi/host/pci_generic.c           | 45 ++++++++++++++++++++++++++++
>  2 files changed, 70 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/bus/mhi/host/clients/sahara/sahara.c b/drivers/bus/mhi/host/clients/sahara/sahara.c
> index e339c67e236af271645ca81cc517efd9eead87e4..9adbd84859073d8024ba2a5fcfa33897439d6759 100644
> --- a/drivers/bus/mhi/host/clients/sahara/sahara.c
> +++ b/drivers/bus/mhi/host/clients/sahara/sahara.c
> @@ -189,6 +189,7 @@ static bool is_streaming(struct sahara_context *context)
>  
>  static int sahara_find_image(struct sahara_context *context, u32 image_id)
>  {
> +	char *fw_path;
>  	int ret;
>  
>  	if (image_id == context->active_image_id)
> @@ -201,8 +202,28 @@ static int sahara_find_image(struct sahara_context *context, u32 image_id)
>  	}
>  
>  	if (image_id >= context->table_size || !context->image_table[image_id]) {
> -		dev_err(&context->mhi_dev->dev, "request for unknown image: %d\n", image_id);
> -		return -EINVAL;
> +		if (!context->fw_folder) {
> +			dev_err(&context->mhi_dev->dev,
> +				"Request for unknown image: %u (no fw folder)\n", image_id);
> +			return -EINVAL;
> +		}
> +
> +		fw_path = kasprintf(GFP_KERNEL, "qcom/%s/%u",
> +				    context->fw_folder, image_id);
> +		if (!fw_path)
> +			return -ENOMEM;
> +
> +		ret = firmware_request_nowarn(&context->firmware,
> +					      fw_path,
> +					      &context->mhi_dev->dev);
> +		kfree(fw_path);
> +		if (ret) {
> +			dev_err(&context->mhi_dev->dev,
> +				"request for unknown image: %d\n", image_id);
> +			return -EINVAL;
> +		}
> +		context->active_image_id = image_id;
> +		return 0;
>  	}
>  
>  	/*
> @@ -870,8 +891,10 @@ static void sahara_mhi_dl_xfer_cb(struct mhi_device *mhi_dev, struct mhi_result
>  
>  static const struct mhi_device_id sahara_mhi_match_table[] = {
>  	{ .chan = "QAIC_SAHARA", },
> +	{ .chan = "SAHARA"},
>  	{},
>  };
> +MODULE_DEVICE_TABLE(mhi, sahara_mhi_match_table);
>  

This change should belong to a separate patch.

>  static struct mhi_driver sahara_mhi_driver = {
>  	.id_table = sahara_mhi_match_table,
> diff --git a/drivers/bus/mhi/host/pci_generic.c b/drivers/bus/mhi/host/pci_generic.c
> index 391ab146f501c6ce1c81f6138f7c491a49c2f264..82e41632afc555a53dec3d8395558ae039b33bbd 100644
> --- a/drivers/bus/mhi/host/pci_generic.c
> +++ b/drivers/bus/mhi/host/pci_generic.c
> @@ -300,6 +300,43 @@ static const struct mhi_pci_dev_info mhi_qcom_qdu100_info = {
>  	.reset_on_remove = true,
>  };
>  
> +static const char * const qdu100_image_table[] = {
> +	[5] = "qcom/qdu100/uefi.elf",
> +	[8] = "qcom/qdu100/qdsp6sw.mbn",
> +	[16] = "qcom/qdu100/efs1.bin",
> +	[17] = "qcom/qdu100/efs2.bin",
> +	[20] = "qcom/qdu100/efs3.bin",
> +	[23] = "qcom/qdu100/aop.mbn",
> +	[25] = "qcom/qdu100/tz.mbn",
> +	[29] = "qcom/qdu100/zeros_1sector.bin",
> +	[33] = "qcom/qdu100/hypvm.mbn",
> +	[34] = "qcom/qdu100/mdmddr.mbn",
> +	[36] = "qcom/qdu100/multi_image_qti.mbn",
> +	[37] = "qcom/qdu100/multi_image.mbn",
> +	[38] = "qcom/qdu100/xbl_config.elf",
> +	[39] = "qcom/qdu100/abl_userdebug.elf",
> +	[40] = "qcom/qdu100/zeros_1sector.bin",
> +	[41] = "qcom/qdu100/devcfg.mbn",
> +	[42] = "qcom/qdu100/zeros_1sector.bin",
> +	[45] = "qcom/qdu100/tools_l.elf",
> +	[46] = "qcom/qdu100/Quantum.elf",
> +	[47] = "qcom/qdu100/quest.elf",
> +	[48] = "qcom/qdu100/xbl_ramdump.elf",
> +	[49] = "qcom/qdu100/shrm.elf",
> +	[50] = "qcom/qdu100/cpucp.elf",
> +	[51] = "qcom/qdu100/aop_devcfg.mbn",
> +	[52] = "qcom/qdu100/fw_csm_gsi_3.0.elf",
> +	[53] = "qcom/qdu100/qdsp6sw_dtbs.elf",
> +	[54] = "qcom/qdu100/qupv3fw.elf",
> +};
> +
> +static const struct mhi_sahara_fw_table qdu100_sahara_fw = {
> +	.image_table = qdu100_image_table,
> +	.table_size = ARRAY_SIZE(qdu100_image_table),
> +	.fw_folder = "qdu100",
> +	.non_streaming = false,
> +};
> +
>  static const struct mhi_channel_config mhi_qcom_sa8775p_channels[] = {
>  	MHI_CHANNEL_CONFIG_UL(46, "IP_SW0", 2048, 1),
>  	MHI_CHANNEL_CONFIG_DL(47, "IP_SW0", 2048, 2),
> @@ -1399,6 +1436,14 @@ static int mhi_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>  
>  	pci_set_drvdata(pdev, mhi_pdev);
>  
> +	/*
> +	 * Provide Sahara firmware mapping. Sahara consumes it via
> +	 * mhi_dev->mhi_cntrl->sahara_fw at probe time.
> +	 */
> +	if (info == &mhi_qcom_qdu100_info ||
> +	    (info->name && !strcmp(info->name, "qcom-qdu100")))
> +		mhi_cntrl->sahara_fw = &qdu100_sahara_fw;
> +

Why are you adding QAIC MHI controller config in pci_generic driver? This driver
only handles Modem devices.

- Mani

-- 
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