[Intel-wired-lan] [PATCH] pci: Use a bus-global mutex to protect VPD operations
Mark D Rustad
mark.d.rustad at intel.com
Sat May 16 00:14:07 UTC 2015
Some devices have a problem with concurrent VPD access to different
functions of the same physical device, so move the protecting mutex
from the pci_vpd structure to the pci_bus structure. There are a
number of reports on support sites for a variety of devices from
various vendors getting the "vpd r/w failed" message. This is likely
to at least fix some of them. Thanks to Shannon Nelson for helping
to come up with this approach.
Signed-off-by: Mark Rustad <mark.d.rustad at intel.com>
---
drivers/pci/access.c | 10 ++++------
drivers/pci/probe.c | 1 +
include/linux/pci.h | 1 +
3 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/drivers/pci/access.c b/drivers/pci/access.c
index d9b64a175990..6a1c8d6f95f1 100644
--- a/drivers/pci/access.c
+++ b/drivers/pci/access.c
@@ -281,7 +281,6 @@ PCI_USER_WRITE_CONFIG(dword, u32)
struct pci_vpd_pci22 {
struct pci_vpd base;
- struct mutex lock;
u16 flag;
bool busy;
u8 cap;
@@ -340,7 +339,7 @@ static ssize_t pci_vpd_pci22_read(struct pci_dev *dev, loff_t pos, size_t count,
if (pos < 0 || pos > vpd->base.len || end > vpd->base.len)
return -EINVAL;
- if (mutex_lock_killable(&vpd->lock))
+ if (mutex_lock_killable(&dev->bus->vpd_mutex))
return -EINTR;
ret = pci_vpd_pci22_wait(dev);
@@ -376,7 +375,7 @@ static ssize_t pci_vpd_pci22_read(struct pci_dev *dev, loff_t pos, size_t count,
}
}
out:
- mutex_unlock(&vpd->lock);
+ mutex_unlock(&dev->bus->vpd_mutex);
return ret ? ret : count;
}
@@ -392,7 +391,7 @@ static ssize_t pci_vpd_pci22_write(struct pci_dev *dev, loff_t pos, size_t count
if (pos < 0 || (pos & 3) || (count & 3) || end > vpd->base.len)
return -EINVAL;
- if (mutex_lock_killable(&vpd->lock))
+ if (mutex_lock_killable(&dev->bus->vpd_mutex))
return -EINTR;
ret = pci_vpd_pci22_wait(dev);
@@ -424,7 +423,7 @@ static ssize_t pci_vpd_pci22_write(struct pci_dev *dev, loff_t pos, size_t count
pos += sizeof(u32);
}
out:
- mutex_unlock(&vpd->lock);
+ mutex_unlock(&dev->bus->vpd_mutex);
return ret ? ret : count;
}
@@ -453,7 +452,6 @@ int pci_vpd_pci22_init(struct pci_dev *dev)
vpd->base.len = PCI_VPD_PCI22_SIZE;
vpd->base.ops = &pci_vpd_pci22_ops;
- mutex_init(&vpd->lock);
vpd->cap = cap;
vpd->busy = false;
dev->vpd = &vpd->base;
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 6675a7a1b9fc..40c2a5a751d0 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -494,6 +494,7 @@ static struct pci_bus *pci_alloc_bus(struct pci_bus *parent)
INIT_LIST_HEAD(&b->devices);
INIT_LIST_HEAD(&b->slots);
INIT_LIST_HEAD(&b->resources);
+ mutex_init(&b->vpd_mutex);
b->max_bus_speed = PCI_SPEED_UNKNOWN;
b->cur_bus_speed = PCI_SPEED_UNKNOWN;
#ifdef CONFIG_PCI_DOMAINS_GENERIC
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 353db8dc4c6e..f8a51d172255 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -454,6 +454,7 @@ struct pci_bus {
struct msi_controller *msi; /* MSI controller */
void *sysdata; /* hook for sys-specific extension */
struct proc_dir_entry *procdir; /* directory entry in /proc/bus/pci */
+ struct mutex vpd_mutex; /* bus-wide VPD access mutex */
unsigned char number; /* bus number */
unsigned char primary; /* number of primary bridge */
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