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

On 7/9/2026 11:49 AM, Manivannan Sadhasivam wrote:
> 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.

There was a review comment from Jeff(v4, patch 3) to move to this change 
to the patch which adds QDU100 support so that it doesn't break bisect. 
Please let me know if i need to move it to a separate patch altogether ?

>
>>   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
>