From mboxrd@z Thu Jan 1 00:00:00 1970 From: will.deacon@arm.com (Will Deacon) Date: Mon, 23 Nov 2015 13:47:28 +0000 Subject: [PATCH 2/3] drivers: pci: host-generic: claim bus resources on PROBE_ONLY set-ups In-Reply-To: <1447779838-15585-2-git-send-email-lorenzo.pieralisi@arm.com> References: <1447779838-15585-1-git-send-email-lorenzo.pieralisi@arm.com> <1447779838-15585-2-git-send-email-lorenzo.pieralisi@arm.com> Message-ID: <20151123134727.GA4236@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Nov 17, 2015 at 05:03:57PM +0000, Lorenzo Pieralisi wrote: > The PCI host generic driver does not reassign bus resources on systems > that require the BARs set-up to be immutable (ie PROBE_ONLY) since > that would trigger system failures. Nonetheless, PCI bus resources > allocated to PCI bridge and devices must be claimed in order to be > validated and inserted in the kernel resource tree, but the current > driver omits the resources claiming and relies on arch specific kludges > to prevent probing failure (ie preventing resources enablement on > PROBE_ONLY systems). > > This patch adds code to the PCI host generic driver that correctly > claims bus resources upon probe on systems that are required to > prevent reassignment after bus enumeration, so that the allocated > resources can be enabled successfully upon PCI device drivers probing, > without resorting to arch back-ends workarounds. > > Signed-off-by: Lorenzo Pieralisi > Cc: Arnd Bergmann > Cc: David Daney > Cc: Will Deacon > Cc: Bjorn Helgaas > --- > drivers/pci/host/pci-host-generic.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) Assuming patch one is accepted, then this looks fine to me: Acked-by: Will Deacon Will > diff --git a/drivers/pci/host/pci-host-generic.c b/drivers/pci/host/pci-host-generic.c > index 5434c90..c62d13f 100644 > --- a/drivers/pci/host/pci-host-generic.c > +++ b/drivers/pci/host/pci-host-generic.c > @@ -261,7 +261,10 @@ static int gen_pci_probe(struct platform_device *pdev) > > pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci); > > - if (!pci_has_flag(PCI_PROBE_ONLY)) { > + > + if (pci_has_flag(PCI_PROBE_ONLY)) { > + pci_bus_claim_resources(bus); > + } else { > pci_bus_size_bridges(bus); > pci_bus_assign_resources(bus); > > -- > 2.5.1 >