From: Bjorn Helgaas <helgaas@kernel.org>
To: Oza Pawandeep <poza@codeaurora.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>,
Philippe Ombredanne <pombredanne@nexb.com>,
Thomas Gleixner <tglx@linutronix.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Kate Stewart <kstewart@linuxfoundation.org>,
linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
Dongdong Liu <liudongdong3@huawei.com>,
Keith Busch <keith.busch@intel.com>, Wei Zhang <wzhang@fb.com>,
Sinan Kaya <okaya@codeaurora.org>,
Timur Tabi <timur@codeaurora.org>
Subject: Re: [PATCH v11 6/7] PCI: Unify wait for link active into generic pci
Date: Sat, 24 Feb 2018 09:41:15 -0600 [thread overview]
Message-ID: <20180224154115.GT14632@bhelgaas-glaptop.roam.corp.google.com> (raw)
In-Reply-To: <1519374244-20539-7-git-send-email-poza@codeaurora.org>
In subject:
s/pci/PCI/
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 <poza@codeaurora.org>
>
> 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/
> + * @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.
> 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
> /* 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.
>
next prev parent reply other threads:[~2018-02-24 15:41 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-23 8:23 [PATCH v11 0/7] Address error and recovery for AER and DPC Oza Pawandeep
2018-02-23 8:23 ` [PATCH v11 1/7] PCI/AER: Rename error recovery to generic pci naming Oza Pawandeep
2018-02-23 8:23 ` [PATCH v11 2/7] PCI/AER: factor out error reporting from AER Oza Pawandeep
2018-02-23 23:42 ` Bjorn Helgaas
2018-02-26 5:32 ` poza
2018-02-26 5:39 ` poza
2018-02-26 20:23 ` Bjorn Helgaas
2018-02-23 8:24 ` [PATCH v11 3/7] PCI/ERR: add mutex to synchronize recovery Oza Pawandeep
2018-02-23 23:45 ` Bjorn Helgaas
2018-02-27 5:16 ` poza
2018-02-27 14:41 ` Bjorn Helgaas
2018-02-23 8:24 ` [PATCH v11 4/7] PCI/DPC: Unify and plumb error handling into DPC Oza Pawandeep
2018-02-24 0:07 ` Bjorn Helgaas
2018-02-27 6:06 ` poza
2018-02-23 8:24 ` [PATCH v11 5/7] PCI/AER: Unify aer error defines at single space Oza Pawandeep
2018-02-24 15:36 ` Bjorn Helgaas
2018-02-27 6:12 ` poza
2018-02-23 8:24 ` [PATCH v11 6/7] PCI: Unify wait for link active into generic pci Oza Pawandeep
2018-02-24 15:41 ` Bjorn Helgaas [this message]
2018-02-27 8:39 ` poza
2018-02-23 8:24 ` [PATCH v11 7/7] PCI/DPC: Enumerate the devices after DPC trigger event Oza Pawandeep
2018-02-23 23:12 ` [PATCH v11 0/7] Address error and recovery for AER and DPC Bjorn Helgaas
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