Commit 12543f44 authored by Vivek Pernamitta's avatar Vivek Pernamitta Committed by Manivannan Sadhasivam
Browse files

bus: mhi: host: pci_generic: Reset QDU100 while the MHI driver is removed 



So, When the MHI driver is removed from the host side, it is essential to
ensure a clean and stable recovery of the device. This commit introduces
the following steps to achieve that:

1. Disable SR-IOV for any SR-IOV-enabled devices on the Physical Function.
2. Perform a SOC_RESET on the PF to fully reset the device.

Disabling SR-IOV ensures all Virtual Functions (VFs) are properly shutdown,
preventing issues during the reset process. The SOC_RESET guarantees that
the PF is restored to a known good state.

If soc_reset is not performed device at driver remove, device will be
stuck in mission mode state and subsequent driver insert/power_up will not
proceed further.

Signed-off-by: default avatarVivek Pernamitta <quic_vpernami@quicinc.com>
[mani: reworded subject]
Signed-off-by: default avatarManivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
Link: https://patch.msgid.link/20250912-uevent_vdev_next-20250911-v4-4-fa2f6ccd301b@quicinc.com
parent fd6e0509

drivers/bus/mhi/host/pci_generic.c

+12 −0
Original line number Diff line number Diff line
@@ -45,6 +45,7 @@ 
 * @sideband_wake: Devices using dedicated sideband GPIO for wakeup instead

 *		   of inband wake support (such as sdx24)

 * @no_m3: M3 not supported

 * @reset_on_remove: Set true for devices that require SoC during driver removal

 */

struct mhi_pci_dev_info {

	const struct mhi_controller_config *config;
@@ -58,6 +59,7 @@ struct mhi_pci_dev_info { 
	unsigned int mru_default;

	bool sideband_wake;

	bool no_m3;

	bool reset_on_remove;

};



#define MHI_CHANNEL_CONFIG_UL(ch_num, ch_name, el_count, ev_ring) \
@@ -300,6 +302,7 @@ static const struct mhi_pci_dev_info mhi_qcom_qdu100_info = { 
	.dma_data_width = 32,

	.sideband_wake = false,

	.no_m3 = true,

	.reset_on_remove = true,

};



static const struct mhi_channel_config mhi_qcom_sa8775p_channels[] = {
@@ -1027,6 +1030,7 @@ struct mhi_pci_device { 
	struct work_struct recovery_work;

	struct timer_list health_check_timer;

	unsigned long status;

	bool reset_on_remove;

};



static int mhi_pci_read_reg(struct mhi_controller *mhi_cntrl,
@@ -1332,6 +1336,9 @@ static int mhi_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) 
	mhi_cntrl->mru = info->mru_default;

	mhi_cntrl->name = info->name;



	if (pdev->is_physfn)

		mhi_pdev->reset_on_remove = info->reset_on_remove;



	if (info->edl_trigger)

		mhi_cntrl->edl_trigger = mhi_pci_generic_edl_trigger;
@@ -1404,6 +1411,8 @@ static void mhi_pci_remove(struct pci_dev *pdev) 
	struct mhi_pci_device *mhi_pdev = pci_get_drvdata(pdev);

	struct mhi_controller *mhi_cntrl = &mhi_pdev->mhi_cntrl;



	pci_disable_sriov(pdev);



	if (pdev->is_physfn)

		timer_delete_sync(&mhi_pdev->health_check_timer);

	cancel_work_sync(&mhi_pdev->recovery_work);
@@ -1417,6 +1426,9 @@ static void mhi_pci_remove(struct pci_dev *pdev) 
	if (pci_pme_capable(pdev, PCI_D3hot))

		pm_runtime_get_noresume(&pdev->dev);



	if (mhi_pdev->reset_on_remove)

		mhi_soc_reset(mhi_cntrl);



	mhi_unregister_controller(mhi_cntrl);

}