Re: [PATCH] PCI/sysfs: Check IORESOURCE_DISABLED in resource mmap handler

["Krzysztof Wilczyński" <kwilczynski@kernel.org>]

Hello,

> Thank you, but as you suggested above, I will update the patch to use
> pci_dev_is_disconnected() instead.

There also exists pci_device_is_present() which would attempt an actual
read of a vendor/device IDs, so if this succeeds, then you have a more
solid assurance that the device should be working.  However, this adds
latency, and there might be side-effects, potentially...

I wonder, if for you, you could forfeit setting any flags on a resource,
which drivers don't customarily do, such that we would only rely on
checking pci_dev_is_disconnected() on our side, so to speak.

We won't be setting any precedent here, as the helpers such as
pci_read_config_byte(), perform this check internally already.

Bjorn and Ilpo might have different take on this, though.

Thank you!

	Krzysztof