[PATCH V2 06/10] i3c: mipi-i3c-hci-pci: Enable MSI support

[Frank Li]

On Mon, Dec 15, 2025 at 07:26:55PM +0200, Adrian Hunter wrote:
> On 12/12/2025 19:38, Frank Li wrote:
> > On Thu, Dec 11, 2025 at 06:19:56PM +0200, Adrian Hunter wrote:
> >> On 11/12/2025 17:40, Frank Li wrote:
> >>> On Thu, Dec 11, 2025 at 03:48:05PM +0200, Adrian Hunter wrote:
> >>>> Use pci_alloc_irq_vectors() to support all IRQ types.  Do not call
> >>>> pci_free_irq_vectors() because it is unnecessary when the device is
> >>>> managed due to the use of pcim_enable_device().
> >>>
> >>> pcim_enable_device() add action pcim_disable_device(), I have not see
> >>> pci_free_irq_vectors() in pcim_disable_device().
> >>>
> >>> Can you tell me where call pci_free_irq_vectors?
> >>
> >> pci_alloc_irq_vectors()
> >> 	pci_alloc_irq_vectors_affinity()
> >> 		__pci_enable_msix_range()
> >> 			pci_setup_msi_context()
> >> 				pcim_setup_msi_release()
> >> 					devm_add_action(pcim_msi_release)
> >> 							:
> >> 							pci_free_irq_vectors()
> >> 		__pci_enable_msi_range()
> >> 			pci_setup_msi_context()
> >
> > Okay, it should be that pci_alloc_irq_vectors() provide auto free. not
> > because pcim_enable_device()?
>
> No, it is conditional on pci_is_managed(dev) which is true if
> pcim_enable_device() has been used.

I have not found any document said that,

 * Managed pci_enable_device(). Device will automatically be disabled on
 * driver detach.

which have not mentioned that it also controller free irqs.

I suggest commit message descript whole story or change PCI's document
to descript it clearly. I think other person should have similar question
if he have not closely follow PCI's change and go through PCI codes.

Frank

>
> >
> > The below statement should be wrong.
> >
> > "Do not call pci_free_irq_vectors() because it is unnecessary when the device is
> > managed due to the use of pcim_enable_device()."
> >
> > Frank
> >>
> >>>
> >>> And move these small patch ahead in serise.
> >>>
> >>> Frank
> >>>>
> >>>> Signed-off-by: Adrian Hunter <adrian.hunter at intel.com>
> >>>> ---
> >>>>
> >>>>
> >>>> 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)
> >>>> --
> >>>> 2.51.0
> >>>>
> >>>>
> >>>> --
> >>>> linux-i3c mailing list
> >>>> linux-i3c at lists.infradead.org
> >>>> http://lists.infradead.org/mailman/listinfo/linux-i3c
> >>
> >>
> >> --
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> >> linux-i3c at lists.infradead.org
> >> http://lists.infradead.org/mailman/listinfo/linux-i3c
>
>
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