From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: Subject: Re: [PATCH v11 2/4] PCI: Factor out pci_bus_wait_crs() To: Bjorn Helgaas References: <20170818212310.15145.21732.stgit@bhelgaas-glaptop.roam.corp.google.com> <20170818213210.15145.15340.stgit@bhelgaas-glaptop.roam.corp.google.com> From: Sinan Kaya Message-ID: <9cb3006d-31d0-e57a-fd3e-c32914e8ba42@codeaurora.org> Date: Mon, 21 Aug 2017 09:53:56 -0400 MIME-Version: 1.0 In-Reply-To: <20170818213210.15145.15340.stgit@bhelgaas-glaptop.roam.corp.google.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-pci@vger.kernel.org, Timur Tabi , linux-kernel@vger.kernel.org, Alex Williamson , linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+bjorn=helgaas.com@lists.infradead.org List-ID: On 8/18/2017 5:32 PM, Bjorn Helgaas wrote: > + if ((*l & 0xffff) != 0x0001) > + return true; /* not a CRS completion */ > This version certainly looks cleaner. However, it breaks pci_flr_wait(). If some root port doesn't support CRS and returns 0xFFFFFFFF, pci_bus_wait_crs() function returns true. pci_flr_wait() prematurely bails out from here. pci_flr_wait() { + ret = pci_bus_wait_crs(dev->bus, dev->devfn, &id, 60000); + if (ret) + return; } We can change the return code to false above but then we break pci_bus_read_dev_vendor_id() function. That's why, I was interested in creating a pci_bus_crs_visibility_supported() helper function that would check for the magic 0x0001 value and return true. Otherwise, false. pci_bus_read_dev_vendor_id() would do this pci_bus_read_dev_vendor_id() { ... if (pci_bus_crs_visibility_supported()) return pci_bus_wait_crs(dev->bus, dev->devfn, &id, 60000); return true } Similar pattern for pci_flr_wait(). -- Sinan Kaya Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel