From mboxrd@z Thu Jan 1 00:00:00 1970 From: lorenzo.pieralisi@arm.com (Lorenzo Pieralisi) Date: Wed, 20 Jan 2016 12:38:49 +0000 Subject: [PATCH V3 11/21] pci, acpi: Move ACPI host bridge device companion assignment to core code. In-Reply-To: <569F6D67.5000000@semihalf.com> References: <1452691267-32240-1-git-send-email-tn@semihalf.com> <1452691267-32240-12-git-send-email-tn@semihalf.com> <20160119160224.GD5276@red-moon> <569F6D67.5000000@semihalf.com> Message-ID: <20160120123849.GA13437@red-moon> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, Jan 20, 2016 at 12:20:07PM +0100, Tomasz Nowicki wrote: > On 19.01.2016 17:02, Lorenzo Pieralisi wrote: > >On Wed, Jan 13, 2016 at 02:20:57PM +0100, Tomasz Nowicki wrote: > [...] > >>device via pci_create_root_bus parameter (as the ACPI device type) > > > >I do not understand what you mean by "as the ACPI device type". > > See below. > > > > >>and using ACPI_COMPANION_SET in core code for ACPI boot method. > >>ACPI_COMPANION_SET is safe to run for all cases DT, ACPI and DT&ACPI. > >> > >>Suggested-by: Lorenzo Pieralisi > >>Signed-off-by: Tomasz Nowicki > >>--- > >> drivers/acpi/pci_root.c | 5 ++++- > >> drivers/pci/probe.c | 2 ++ > >> 2 files changed, 6 insertions(+), 1 deletion(-) > >> > >>diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c > >>index ae3fe4e..a65c8c2 100644 > >>--- a/drivers/acpi/pci_root.c > >>+++ b/drivers/acpi/pci_root.c > >>@@ -846,7 +846,10 @@ struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root, > >> > >> pci_acpi_root_add_resources(info); > >> pci_add_resource(&info->resources, &root->secondary); > >>- bus = pci_create_root_bus(NULL, busnum, ops->pci_ops, > >>+ > >>+ /* Root bridge device needs to be sure of parent ACPI type */ > >>+ ACPI_COMPANION_SET(&device->dev, device); > > > >I do not understand why the code above is needed, can you elaborate > >please ? > > > > This makes sure that device->dev can be identified as ACPI device, > so we can use to_acpi_device_node() and assign companion safely > below. I do not follow. If you refer to the fwnode handle type, that is already set by ACPI core code (before acpi_pci_root_add() is called, in acpi_init_device_object()). Did you add the code above to solve a real issue you encountered ? Thanks, Lorenzo