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

[Manivannan Sadhasivam]

On Mon, Jul 13, 2026 at 07:46:02PM +0530, Kishore Batta wrote:
> 
> 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 <kishore.batta@xxxxxxxxxxxxxxxx>
> > > ---
> > >   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
> 
> 
> Hi Mani, Above one is for QDU100 device. QAIC is not added in this file.
> 

Sorry, my bad. But anyhow, you should provide this mapping table pointer via
'struct mhi_pci_dev_info'.

- Mani

-- 
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