releases/3.6.8/pci-pm-fix-proc-config-reg-access-for-d3cold-and-bridge-suspending.patch

   1 From b3c32c4f9565f93407921c0d8a4458042eb8998e Mon Sep 17 00:00:00 2001
   2 From: Huang Ying <ying.huang@intel.com>
   3 Date: Thu, 25 Oct 2012 09:36:03 +0800
   4 Subject: PCI/PM: Fix proc config reg access for D3cold and bridge suspending
   5
   6 From: Huang Ying <ying.huang@intel.com>
   7
   8 commit b3c32c4f9565f93407921c0d8a4458042eb8998e upstream.
   9
  10 In https://bugzilla.kernel.org/show_bug.cgi?id=48981
  11 Peter reported that /proc/bus/pci/??/??.? does not work for 3.6.
  12 This is because the device configuration space registers are
  13 not accessible if the corresponding parent bridge is suspended or
  14 the device is put into D3cold state.
  15
  16 This is the same as /sys/bus/pci/devices/0000:??:??.?/config access
  17 issue.  So the function used to solve sysfs issue is used to solve
  18 this issue.
  19
  20 This patch moves pci_config_pm_runtime_get()/_put() from pci/pci-sysfs.c
  21 to pci/pci.c and makes them extern so they can be used by both the
  22 sysfs and proc paths.
  23
  24 [bhelgaas: changelog, references, reporters]
  25 Reference: https://bugzilla.kernel.org/show_bug.cgi?id=48981
  26 Reference: https://bugzilla.kernel.org/show_bug.cgi?id=49031
  27 Reported-by: Forrest Loomis <cybercyst@gmail.com>
  28 Reported-by: Peter <lekensteyn@gmail.com>
  29 Reported-by: Micael Dias <kam1kaz3@gmail.com>
  30 Signed-off-by: Huang Ying <ying.huang@intel.com>
  31 Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
  32 Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
  33 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  34
  35 ---
  36  drivers/pci/pci-sysfs.c |   34 ----------------------------------
  37  drivers/pci/pci.c       |   32 ++++++++++++++++++++++++++++++++
  38  drivers/pci/pci.h       |    2 ++
  39  drivers/pci/proc.c      |    8 ++++++++
  40  4 files changed, 42 insertions(+), 34 deletions(-)
  41
  42 --- a/drivers/pci/pci-sysfs.c
  43 +++ b/drivers/pci/pci-sysfs.c
  44 @@ -458,40 +458,6 @@ boot_vga_show(struct device *dev, struct
  45  }
  46  struct device_attribute vga_attr = __ATTR_RO(boot_vga);
  47
  48 -static void
  49 -pci_config_pm_runtime_get(struct pci_dev *pdev)
  50 -{
  51 -       struct device *dev = &pdev->dev;
  52 -       struct device *parent = dev->parent;
  53 -
  54 -       if (parent)
  55 -               pm_runtime_get_sync(parent);
  56 -       pm_runtime_get_noresume(dev);
  57 -       /*
  58 -        * pdev->current_state is set to PCI_D3cold during suspending,
  59 -        * so wait until suspending completes
  60 -        */
  61 -       pm_runtime_barrier(dev);
  62 -       /*
  63 -        * Only need to resume devices in D3cold, because config
  64 -        * registers are still accessible for devices suspended but
  65 -        * not in D3cold.
  66 -        */
  67 -       if (pdev->current_state == PCI_D3cold)
  68 -               pm_runtime_resume(dev);
  69 -}
  70 -
  71 -static void
  72 -pci_config_pm_runtime_put(struct pci_dev *pdev)
  73 -{
  74 -       struct device *dev = &pdev->dev;
  75 -       struct device *parent = dev->parent;
  76 -
  77 -       pm_runtime_put(dev);
  78 -       if (parent)
  79 -               pm_runtime_put_sync(parent);
  80 -}
  81 -
  82  static ssize_t
  83  pci_read_config(struct file *filp, struct kobject *kobj,
  84                 struct bin_attribute *bin_attr,
  85 --- a/drivers/pci/pci.c
  86 +++ b/drivers/pci/pci.c
  87 @@ -1910,6 +1910,38 @@ bool pci_dev_run_wake(struct pci_dev *de
  88  }
  89  EXPORT_SYMBOL_GPL(pci_dev_run_wake);
  90
  91 +void pci_config_pm_runtime_get(struct pci_dev *pdev)
  92 +{
  93 +       struct device *dev = &pdev->dev;
  94 +       struct device *parent = dev->parent;
  95 +
  96 +       if (parent)
  97 +               pm_runtime_get_sync(parent);
  98 +       pm_runtime_get_noresume(dev);
  99 +       /*
 100 +        * pdev->current_state is set to PCI_D3cold during suspending,
 101 +        * so wait until suspending completes
 102 +        */
 103 +       pm_runtime_barrier(dev);
 104 +       /*
 105 +        * Only need to resume devices in D3cold, because config
 106 +        * registers are still accessible for devices suspended but
 107 +        * not in D3cold.
 108 +        */
 109 +       if (pdev->current_state == PCI_D3cold)
 110 +               pm_runtime_resume(dev);
 111 +}
 112 +
 113 +void pci_config_pm_runtime_put(struct pci_dev *pdev)
 114 +{
 115 +       struct device *dev = &pdev->dev;
 116 +       struct device *parent = dev->parent;
 117 +
 118 +       pm_runtime_put(dev);
 119 +       if (parent)
 120 +               pm_runtime_put_sync(parent);
 121 +}
 122 +
 123  /**
 124   * pci_pm_init - Initialize PM functions of given PCI device
 125   * @dev: PCI device to handle.
 126 --- a/drivers/pci/pci.h
 127 +++ b/drivers/pci/pci.h
 128 @@ -72,6 +72,8 @@ extern void pci_disable_enabled_device(s
 129  extern int pci_finish_runtime_suspend(struct pci_dev *dev);
 130  extern int __pci_pme_wakeup(struct pci_dev *dev, void *ign);
 131  extern void pci_wakeup_bus(struct pci_bus *bus);
 132 +extern void pci_config_pm_runtime_get(struct pci_dev *dev);
 133 +extern void pci_config_pm_runtime_put(struct pci_dev *dev);
 134  extern void pci_pm_init(struct pci_dev *dev);
 135  extern void platform_pci_wakeup_init(struct pci_dev *dev);
 136  extern void pci_allocate_cap_save_buffers(struct pci_dev *dev);
 137 --- a/drivers/pci/proc.c
 138 +++ b/drivers/pci/proc.c
 139 @@ -76,6 +76,8 @@ proc_bus_pci_read(struct file *file, cha
 140         if (!access_ok(VERIFY_WRITE, buf, cnt))
 141                 return -EINVAL;
 142
 143 +       pci_config_pm_runtime_get(dev);
 144 +
 145         if ((pos & 1) && cnt) {
 146                 unsigned char val;
 147                 pci_user_read_config_byte(dev, pos, &val);
 148 @@ -121,6 +123,8 @@ proc_bus_pci_read(struct file *file, cha
 149                 cnt--;
 150         }
 151
 152 +       pci_config_pm_runtime_put(dev);
 153 +
 154         *ppos = pos;
 155         return nbytes;
 156  }
 157 @@ -146,6 +150,8 @@ proc_bus_pci_write(struct file *file, co
 158         if (!access_ok(VERIFY_READ, buf, cnt))
 159                 return -EINVAL;
 160
 161 +       pci_config_pm_runtime_get(dev);
 162 +
 163         if ((pos & 1) && cnt) {
 164                 unsigned char val;
 165                 __get_user(val, buf);
 166 @@ -191,6 +197,8 @@ proc_bus_pci_write(struct file *file, co
 167                 cnt--;
 168         }
 169
 170 +       pci_config_pm_runtime_put(dev);
 171 +
 172         *ppos = pos;
 173         i_size_write(ino, dp->size);
 174         return nbytes;