From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from metis.ext.pengutronix.de ([92.198.50.35]:54941 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752400AbbC3Kga (ORCPT ); Mon, 30 Mar 2015 06:36:30 -0400 Message-ID: <1427711786.3370.3.camel@pengutronix.de> Subject: Re: [PATCH v3 1/2] PCI: add helper function to find root port for device From: Lucas Stach To: Bjorn Helgaas Cc: Thierry Reding , linux-tegra@vger.kernel.org, linux-pci@vger.kernel.org Date: Mon, 30 Mar 2015 12:36:26 +0200 In-Reply-To: <20150123223424.GN29776@google.com> References: <1421179048-25370-1-git-send-email-l.stach@pengutronix.de> <20150123223424.GN29776@google.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Sender: linux-pci-owner@vger.kernel.org List-ID: Am Freitag, den 23.01.2015, 16:34 -0600 schrieb Bjorn Helgaas: > On Tue, Jan 13, 2015 at 08:57:27PM +0100, Lucas Stach wrote: > > This adds a simple way to get the root port a given device > > is connected to. > > > > Signed-off-by: Lucas Stach > > --- > > v2: new patch in v2 > > v3: rename to pci_find_rootport to fit better with other API > > --- > > drivers/pci/search.c | 20 ++++++++++++++++++++ > > include/linux/pci.h | 1 + > > 2 files changed, 21 insertions(+) > > > > diff --git a/drivers/pci/search.c b/drivers/pci/search.c > > index a20ce7d5e2a7..7254f126096d 100644 > > --- a/drivers/pci/search.c > > +++ b/drivers/pci/search.c > > @@ -384,3 +384,23 @@ int pci_dev_present(const struct pci_device_id *ids) > > return 0; > > } > > EXPORT_SYMBOL(pci_dev_present); > > + > > +/** > > + * pci_find_root_port - Returns the root port the given device is connected to. > > + * @dev: PCI device for which the root port should be found. > > + */ > > +struct pci_dev *pci_find_root_port(struct pci_dev *dev) > > This seems a little too generic. There are still PCI (non-PCIe) systems, > and on those this will return some non-Root Port device, the meaning of > which is unclear. I'm happy to put something like this in pci-tegra.c, but > until there are other potential users and we sort out the PCI/PCIe-ness of > the interface, I don't really want to make it global and exported. > I moved it out of the Tegra PCIe driver on your request. Also I can already see this being useful for the Keystone PCI host driver to shorten the MTRS quirk function. I will rename this to pcie_find_root_port() so it is clear that this is PCIe specific, but keep it in the current location. > > +{ > > + struct pci_bus *bus = dev->bus; > > + > > + /* If there is no bridge on the bus the passed device is a root port. */ > > This assumption is false -- see the comment at pci_is_root_bus(). > Right, will change this. Regards, Lucas -- Pengutronix e.K. | Lucas Stach | Industrial Linux Solutions | http://www.pengutronix.de/ |