Re: [RFC 01/32] Kconfig: introduce and depend on LEGACY_PCI
From: Bjorn Helgaas <helgaas@kernel.org>
Date: 2022-01-06 18:14:20
Also in:
dri-devel, intel-wired-lan, linux-arch, linux-fbdev, linux-gpio, linux-hwmon, linux-i2c, linux-ide, linux-input, linux-media, linux-pci, linux-riscv, linux-scsi, linux-serial, linux-spi, linux-watchdog, linux-wireless, lkml
On Thu, Jan 06, 2022 at 05:41:00PM +0000, John Garry wrote:
On 05/01/2022 19:47, Bjorn Helgaas wrote:
quoted
IMO inb() should be present but do something innocuous like return ~0, as it would if I/O port space is supported but there's no device at that address. [1]https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/scsi/megaraid.c?id=v5.15#n4210That driver would prob not be used on systems which does not support PIO, and so could have a HAS_IOPORT dependency. But it is not strictly necessary.
I don't want the path of "this driver isn't needed because the device is unlikely to be used on this arch." Maybe it's not _always_ possible, but if the device can be plugged into the platform, I think we should be able to build the driver for it. If the device requires I/O port space and the platform doesn't support it, the PCI core or the driver should detect that and give a useful diagnostic. Bjorn