Re: [PATCH v4 1/4] PCI: Introduce pcim_alloc_irq_vectors()

From: Dejin Zheng
Date: Mon Feb 22 2021 - 10:23:32 EST


On Mon, Feb 22, 2021 at 11:56:08AM +0100, Robert Richter wrote:
> On 20.02.21 00:46:49, Dejin Zheng wrote:
> > > On 18.02.21 23:04:55, Dejin Zheng wrote:
>
> > > > + if (!dr || !dr->enabled)
> > here checks whether the pci device is enabled.
>
> What is the purpose of this? The device "is_managed" or not.
>
The device is managed or not by check whether "dr" is NULL. And
check the "dr->enabled" is for the PCI device enable. I think it
may not make sense to apply for irq vectors when PCI device is not
enabled.

PCI device enable by call pci_enable_device() function, this function
initialize device before it's used by a driver. Ask low-level code
to enable I/O and memory. Wake up the device if it was suspended.

So I think it might be better to return to failure when it is found
the PCI device is not enabled in the pcim_alloc_irq_vectors() function.
It can facilitate developers to find problems as soon as possible.

BR,
Dejin
> -Robert