On Fri, Apr 24, 2020 at 12:23:12AM +0200, Pali Rohár wrote: > On Thursday 23 April 2020 17:17:14 Bjorn Helgaas wrote: > > On Thu, Apr 23, 2020 at 09:02:02PM +0200, Pali Rohár wrote: > > > On Thursday 23 April 2020 13:41:51 Bjorn Helgaas wrote: > > > > [+cc Rob] > > > > > > > > On Tue, Apr 21, 2020 at 01:16:56PM +0200, Marek Behún wrote: > > > > > From: Pali Rohár <pali@xxxxxxxxxx> > > > > > > > > > > Add support for issuing PERST via GPIO specified in 'reset-gpios' > > > > > property (as described in PCI device tree bindings). > > > > > > > > > > Some buggy cards (e.g. Compex WLE900VX or WLE1216) are not detected > > > > > after reboot when PERST is not issued during driver initialization. > > > > > > > > Does this slot support hotplug? > > > > > > I have no idea. I have not heard that anybody tried hotplugging cards > > > with this aardvark pcie controller at runtime. > > > > > > This patch fixes initialization only at boot time when cards were > > > plugged prior powering board on. > > > > > > > If so, I don't think this fix will help the hot-add case, will it? > > > > > > I even do not know if aardvark HW supports it. And if yes, I think it is > > > unimplemented and/or broken. > > > > > > In documentation there is some interrupt register which could signal it, > > > but I it is not used by kernel's pci-aardvark.c driver. > > > > "lspci -vv" will show you whether the hardware claims to support it, > > e.g., > > > > 00:1c.0 PCI bridge: Intel Corporation Sunrise Point-LP PCI Express Root Port #1 > > Capabilities: [40] Express (v2) Root Port (Slot+), MSI 00 > > SltCap: AttnBtn- PwrCtrl- MRL- AttnInd- PwrInd- HotPlug- Surprise- > > > > If the right combination of bits are set there, pciehp will claim the > > port and support hotplug. > > aardvark controller does not have pci bridge on bus. Kernel aardvark > driver uses pci_bridge_emul_init() for registering emulated pci bridge. > > Is hotplug flag from that emulated pci bridge relevant here? I doubt it.
