[PATCH V3 05/11] i3c: mipi-i3c-hci-pci: Enable MSI support

Adrian Hunter
2025-12-16T16:57:04Z

Enable MSI support by using pci_alloc_irq_vectors() to request all
supported IRQ types. Do not call pci_free_irq_vectors() because for
resource-managed devices (those initialized with pcim_enable_device()),
IRQ vector allocation is automatically managed. See
pci_setup_msi_context() and pcim_setup_msi_release() for details.

Note: The current documentation for pci_alloc_irq_vectors() does not
mention this behavior.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---

Changes in V3:

Enhance commit message

Changes in V2:
New patch split from "i3c: mipi-i3c-hci-pci: Add support for
Multi-Bus Instances"

drivers/i3c/master/mipi-i3c-hci/mipi-i3c-hci-pci.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/i3c/master/mipi-i3c-hci/mipi-i3c-hci-pci.c b/drivers/i3c/master/mipi-i3c-hci/mipi-i3c-hci-pci.c
index 8ade911e3835..0fd3587671e1 100644
--- a/drivers/i3c/master/mipi-i3c-hci/mipi-i3c-hci-pci.c
+++ b/drivers/i3c/master/mipi-i3c-hci/mipi-i3c-hci-pci.c
@@ -203,6 +203,10 @@ static int mipi_i3c_hci_pci_probe(struct pci_dev *pci,

pci_set_master(pci);

+ ret = pci_alloc_irq_vectors(pci, 1, 1, PCI_IRQ_ALL_TYPES);
+ if (ret < 0)
+ return ret;
+
memset(&res, 0, sizeof(res));

res[0].flags = IORESOURCE_MEM;
@@ -210,8 +214,8 @@ static int mipi_i3c_hci_pci_probe(struct pci_dev *pci,
res[0].end = pci_resource_end(pci, 0);

res[1].flags = IORESOURCE_IRQ;
- res[1].start = pci->irq;
- res[1].end = pci->irq;
+ res[1].start = pci_irq_vector(hci->pci, 0);
+ res[1].end = res[1].start;

dev_id = ida_alloc(&mipi_i3c_hci_pci_ida, GFP_KERNEL);
if (dev_id < 0)