Commit 5fe77a6d authored Mar 06, 2026 by Adrian Hunter Committed by Alexandre Belloni Apr 12, 2026

i3c: mipi-i3c-hci: Add quirk to allow IBI while runtime suspended



Some I3C controllers can be automatically runtime-resumed in order to
handle in-band interrupts (IBIs), meaning that runtime suspend does not
need to be blocked when IBIs are enabled.

For example, a PCI-attached controller in a low-power state may generate
a Power Management Event (PME) when the SDA line is pulled low to signal
the START condition of an IBI. The PCI subsystem will then runtime-resume
the device, allowing the IBI to be received without requiring the
controller to remain active.

Introduce a new quirk, HCI_QUIRK_RPM_IBI_ALLOWED, so that drivers can
opt-in to this capability via driver data.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260306085338.62955-3-adrian.hunter@intel.com


Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

parent 815b4448

drivers/i3c/master/mipi-i3c-hci/core.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -996,6 +996,9 @@ static int i3c_hci_probe(struct platform_device *pdev)
		if (hci->quirks & HCI_QUIRK_RPM_ALLOWED)
		i3c_hci_rpm_enable(&pdev->dev);

		if (hci->quirks & HCI_QUIRK_RPM_IBI_ALLOWED)
		hci->master.rpm_ibi_allowed = true;

		return i3c_master_register(&hci->master, &pdev->dev, &i3c_hci_ops, false);
		}

drivers/i3c/master/mipi-i3c-hci/hci.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -150,6 +150,7 @@ struct i3c_hci_dev_data {
		#define HCI_QUIRK_OD_PP_TIMING BIT(3) /* Set OD and PP timings for AMD platforms */
		#define HCI_QUIRK_RESP_BUF_THLD BIT(4) /* Set resp buf thld to 0 for AMD platforms */
		#define HCI_QUIRK_RPM_ALLOWED BIT(5) /* Runtime PM allowed */
		#define HCI_QUIRK_RPM_IBI_ALLOWED BIT(6) /* IBI and Hot-Join allowed while runtime suspended */

		/* global functions */
		void mipi_i3c_hci_resume(struct i3c_hci *hci);