On 2019/8/13 18:18, Lorenzo Pieralisi wrote: > On Sat, Jun 15, 2019 at 02:48:24PM +0800, Yuehaibing wrote: >> +cc Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> > > Can we drop this patch and merge: > > https://patchwork.ozlabs.org/patch/1131444/ > > instead ? Ok, it looks good to me, thanks! > > Thanks, > Lorenzo > >> >> On 2019/6/15 14:18, Yuehaibing wrote: >>> >>> On 2019/6/2 6:59, Michael Kelley wrote: >>>> From: YueHaibing <yuehaibing@xxxxxxxxxx> Sent: Friday, May 31, 2019 8:09 AM >>>>> >>>>> while building without CONFIG_SYSFS, fails as below: >>>>> >>>>> drivers/pci/controller/pci-hyperv.o: In function 'hv_pci_assign_slots': >>>>> pci-hyperv.c:(.text+0x40a): undefined reference to 'pci_create_slot' >>>>> drivers/pci/controller/pci-hyperv.o: In function 'pci_devices_present_work': >>>>> pci-hyperv.c:(.text+0xc02): undefined reference to 'pci_destroy_slot' >>>>> drivers/pci/controller/pci-hyperv.o: In function 'hv_pci_remove': >>>>> pci-hyperv.c:(.text+0xe50): undefined reference to 'pci_destroy_slot' >>>>> drivers/pci/controller/pci-hyperv.o: In function 'hv_eject_device_work': >>>>> pci-hyperv.c:(.text+0x11f9): undefined reference to 'pci_destroy_slot' >>>>> >>>>> Select SYSFS while PCI_HYPERV is set to fix this. >>>>> >>>> >>>> I'm wondering if is the right way to fix the problem. Conceptually >>>> is it possible to setup & operate virtual PCI devices like >>>> pci-hyperv.c does, even if sysfs is not present? Or is it right to >>>> always required sysfs? >>>> >>>> The function pci_dev_assign_slot() in slot.c has a null implementation >>>> in include/linux/pci.h when CONFIG_SYSFS is not defined, which >>>> seems to be trying to solve the same problem for that function. And >>>> if CONFIG_HOTPLUG_PCI is defined but CONFIG_SYSFS is not, >>>> pci_hp_create_module_link() and pci_hp_remove_module_link() >>>> look like they would have the same problem. Maybe there should >>>> be degenerate implementations of pci_create_slot() and >>>> pci_destroy_slot() for cases when CONFIG_SYSFS is not defined? >>>> >>>> But I'll admit I don't know the full story behind how PCI slots >>>> are represented and used, so maybe I'm off base. I just noticed >>>> the inconsistency in how other functions in slot.c are handled. >>>> >>>> Thoughts? >>> >>> 268a03a42d33 ("PCI: drivers/pci/slot.c should depend on CONFIG_SYSFS") >>> >>> make slot.o depends CONFIG_SYSFS >>> >>> commit 268a03a42d3377d5fb41e6e7cbdec4e0b65cab2e >>> Author: Alex Chiang <achiang@xxxxxx> >>> Date: Wed Jun 17 19:03:57 2009 -0600 >>> >>> PCI: drivers/pci/slot.c should depend on CONFIG_SYSFS >>> >>> There is no way to interact with a physical PCI slot without >>> sysfs, so encode the dependency and prevent this build error: >>> >>> drivers/pci/slot.c: In function 'pci_hp_create_module_link': >>> drivers/pci/slot.c:327: error: 'module_kset' undeclared >>> >>> This patch _should_ make pci-sysfs.o depend on CONFIG_SYSFS too, >>> but we cannot (yet) because the PCI core merrily assumes the >>> existence of sysfs: >>> >>> drivers/built-in.o: In function `pci_bus_add_device': >>> drivers/pci/bus.c:89: undefined reference to `pci_create_sysfs_dev_files' >>> drivers/built-in.o: In function `pci_stop_dev': >>> drivers/pci/remove.c:24: undefined reference to `pci_remove_sysfs_dev_files' >>> >>> So do the minimal bit for now and figure out how to untangle it >>> later. >>> >>> If No CONFIG_SYSFS, slot.o is not build >>> >>>> >>>> Michael >>>> >>>> >>> >>> >>> . >>> >> > > . >
