From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x224HLLo0mFkX+eMdpcwsqVyITD9NzuT4Tjk4UMJf5Wll9yhEYr8Wburpd1QvCN81A3Sw7Xo8 ARC-Seal: i=1; a=rsa-sha256; t=1519720785; cv=none; d=google.com; s=arc-20160816; b=CSIueKsGhKjvH5mhf9yTIteYhcG6YNHC1gtEVFaZw4aYlMHZXJdb+sStBpgce/k6/e 8mJBvc3okddcwisjDAWkuUzw9QwCqUDegZF7X3pdU4sFG8jxOhxcfyn3Nl3pHpavlRmc Q6v0n9STwsh43a0SWuzhcWo6RedyiK7oEjbgs+dkMCjXXHW28CnEXYj3KC0v5u1fF0Js CjBCRF0QjhJWHLsqpqfdKVD7NjfMlgSHzq9PFI9jvccOfB/9/J/vaArM/qCe82/e5XiS 1XNzKLKmkv2Ee+ZHPMCMUnYwfR9CKn5YBfbkvZxhvYJKcVvaXfO1t1J8WtVuf6vpCgcQ hvjg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=user-agent:message-id:references:in-reply-to:subject:cc:to:from :date:content-transfer-encoding:mime-version:dkim-signature :dkim-signature:arc-authentication-results; bh=QeqiOCsZQ4w8e7mkF8SxGvXdhtiGbrsFqe7oByEy4AY=; b=E6g/Ojx5abjL1bh4GRGfX77lJcWaVX/alMEEkJcZpkLROeHV+907mczuVA+AwmClCc qtqvNJuA+2/GGGNvyYYgoDIOhihvHjkgMz+v2BlsYyh81pj4Ig5ouIU94pQ4nL1SObNM GZuIQ/2pNHRd7iIUS5Um32+tg6hJ3DroYr+IfGBzt36I9MhSF/XHFXXnHeHKJxQaqEGb k8ZSS5VOEQOqH64uA3KOWf2cp6UpQ8k82tnTgPj2k0i1HzCm7gA7xztIAo6Is7JjOtx9 e2KLWcjQfcWqDUmMthzzD8S5Chw0VxyRhMzNxYhGR14Aff5V8tQShnkW5ykdjoBAnbqB 8M5w== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@codeaurora.org header.s=default header.b=kPLGL9T0; dkim=pass header.i=@codeaurora.org header.s=default header.b=i9nx3ugO; spf=pass (google.com: domain of poza@codeaurora.org designates 198.145.29.96 as permitted sender) smtp.mailfrom=poza@codeaurora.org Authentication-Results: mx.google.com; dkim=pass header.i=@codeaurora.org header.s=default header.b=kPLGL9T0; dkim=pass header.i=@codeaurora.org header.s=default header.b=i9nx3ugO; spf=pass (google.com: domain of poza@codeaurora.org designates 198.145.29.96 as permitted sender) smtp.mailfrom=poza@codeaurora.org MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Tue, 27 Feb 2018 14:09:43 +0530 From: poza@codeaurora.org To: Bjorn Helgaas Cc: Bjorn Helgaas , Philippe Ombredanne , Thomas Gleixner , Greg Kroah-Hartman , Kate Stewart , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Dongdong Liu , Keith Busch , Wei Zhang , Sinan Kaya , Timur Tabi Subject: Re: [PATCH v11 6/7] PCI: Unify wait for link active into generic pci In-Reply-To: <20180224154115.GT14632@bhelgaas-glaptop.roam.corp.google.com> References: <1519374244-20539-1-git-send-email-poza@codeaurora.org> <1519374244-20539-7-git-send-email-poza@codeaurora.org> <20180224154115.GT14632@bhelgaas-glaptop.roam.corp.google.com> Message-ID: <44250c485313bd1240d8617511f5888c@codeaurora.org> User-Agent: Roundcube Webmail/1.2.5 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1593086424372892434?= X-GMAIL-MSGID: =?utf-8?q?1593542742410497703?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On 2018-02-24 21:11, Bjorn Helgaas wrote: > In subject: > > s/pci/PCI/ sure. > > On Fri, Feb 23, 2018 at 01:54:03PM +0530, Oza Pawandeep wrote: >> Clients such as pciehp, dpc are using pcie_wait_link_active, which >> waits >> till the link becomes active or inactive. > > Use "()" after function names so we have a visual clue that they are > functions. > >> Made generic function and moved it to drivers/pci/pci.c >> >> Signed-off-by: Oza Pawandeep >> >> diff --git a/drivers/pci/hotplug/pciehp_hpc.c >> b/drivers/pci/hotplug/pciehp_hpc.c >> index 18a42f8..de9b0ea 100644 >> --- a/drivers/pci/hotplug/pciehp_hpc.c >> +++ b/drivers/pci/hotplug/pciehp_hpc.c >> @@ -231,25 +231,11 @@ bool pciehp_check_link_active(struct controller >> *ctrl) >> return ret; >> } >> >> -static void __pcie_wait_link_active(struct controller *ctrl, bool >> active) >> +static bool pcie_wait_link_active(struct controller *ctrl) >> { >> - int timeout = 1000; >> - >> - if (pciehp_check_link_active(ctrl) == active) >> - return; >> - while (timeout > 0) { >> - msleep(10); >> - timeout -= 10; >> - if (pciehp_check_link_active(ctrl) == active) >> - return; >> - } >> - ctrl_dbg(ctrl, "Data Link Layer Link Active not %s in 1000 msec\n", >> - active ? "set" : "cleared"); >> -} >> + struct pci_dev *pdev = ctrl_dev(ctrl); >> >> -static void pcie_wait_link_active(struct controller *ctrl) >> -{ >> - __pcie_wait_link_active(ctrl, true); >> + return pci_wait_for_link(pdev, true); >> } >> >> static bool pci_bus_check_dev(struct pci_bus *bus, int devfn) >> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c >> index f6a4dd1..f8d44b4 100644 >> --- a/drivers/pci/pci.c >> +++ b/drivers/pci/pci.c >> @@ -4176,6 +4176,37 @@ static int pci_pm_reset(struct pci_dev *dev, >> int probe) >> return 0; >> } >> >> +/** >> + * pci_wait_for_link - Wait for link till its active/inactive > > s/its/it's/ sure. > >> + * @pdev: Bridge device >> + * @active: waiting for active or inactive ? >> + * >> + * Use this to wait till link becomes active or inactive. >> + */ >> +bool pci_wait_for_link(struct pci_dev *pdev, bool active) > > I think this should be "pcie_wait_for_link()". There's no concept of a > link in conventional PCI. > >> +{ >> + int timeout = 1000; >> + bool ret; >> + u16 lnk_status; >> + >> + for (;;) { >> + pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status); >> + ret = !!(lnk_status & PCI_EXP_LNKSTA_DLLLA); >> + if (ret == active) >> + return true; >> + if (timeout <= 0) >> + break; >> + timeout -= 10; >> + } >> + >> + dev_printk(KERN_DEBUG, &pdev->dev, > > pci_info(). Distros often seem to have logging configured so > KERN_DEBUG things aren't captured, and this definitely seems worth > capturing. > >> + "Data Link Layer Link Active not %s in 1000 msec\n", >> + active ? "set" : "cleared"); >> + >> + return false; >> +} >> +EXPORT_SYMBOL(pci_wait_for_link); > > I don't think this needs to be exported. > sure. >> void pci_reset_secondary_bus(struct pci_dev *dev) >> { >> u16 ctrl; >> diff --git a/drivers/pci/pcie/pcie-dpc.c b/drivers/pci/pcie/pcie-dpc.c >> index 5c01c63..e15bcda 100644 >> --- a/drivers/pci/pcie/pcie-dpc.c >> +++ b/drivers/pci/pcie/pcie-dpc.c >> @@ -120,19 +120,9 @@ static int dpc_wait_rp_inactive(struct dpc_dev >> *dpc) >> >> static void dpc_wait_link_inactive(struct dpc_dev *dpc) >> { >> - unsigned long timeout = jiffies + HZ; >> struct pci_dev *pdev = dpc->dev->port; >> - struct device *dev = &dpc->dev->device; >> - u16 lnk_status; >> >> - pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status); >> - while (lnk_status & PCI_EXP_LNKSTA_DLLLA && >> - !time_after(jiffies, timeout)) { >> - msleep(10); >> - pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status); >> - } >> - if (lnk_status & PCI_EXP_LNKSTA_DLLLA) >> - dev_warn(dev, "Link state not disabled for DPC event\n"); >> + pci_wait_for_link(pdev, false); >> } >> >> /** >> diff --git a/include/linux/pci.h b/include/linux/pci.h >> index 024a1be..cb674c3 100644 >> --- a/include/linux/pci.h >> +++ b/include/linux/pci.h >> @@ -1195,6 +1195,7 @@ int pci_add_ext_cap_save_buffer(struct pci_dev >> *dev, >> int pci_request_selected_regions(struct pci_dev *, int, const char >> *); >> int pci_request_selected_regions_exclusive(struct pci_dev *, int, >> const char *); >> void pci_release_selected_regions(struct pci_dev *, int); >> +bool pci_wait_for_link(struct pci_dev *pdev, bool active); > > I don't think this needs to be available outside the PCI core, so this > could probably be declared in drivers/pci/pci.h > thanks, will move it. >> /* drivers/pci/bus.c */ >> struct pci_bus *pci_bus_get(struct pci_bus *bus); >> -- >> Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm >> Technologies, Inc., >> a Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a >> Linux Foundation Collaborative Project. >>