From: Stanislav Spassov <stanspas@xxxxxxxxx>
A broken device may never become responsive after reset, hence the need
for a timeout. However, waiting for too long can have unintended side
effects such as triggering hung task timeouts for processes waiting on
a lock held during the reset. Locks that are shared across multiple
devices, such as VFIO's per-bus reflck, are especially problematic,
because a single broken VF can cause hangs for processes working with
other VFs on the same bus.
To allow lowering the global default post-reset timeout, while still
accommodating devices that require more time, this patch introduces
a per-device override that can be configured via a quirk.
Signed-off-by: Stanislav Spassov <stanspas@xxxxxxxxx>
---
drivers/pci/pci.c | 19 ++++++++++++++-----
drivers/pci/probe.c | 2 ++
include/linux/pci.h | 1 +
3 files changed, 17 insertions(+), 5 deletions(-)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index db9b58ab6c68..a554818968ed 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1033,8 +1033,17 @@ void pci_wakeup_bus(struct pci_bus *bus)
pci_walk_bus(bus, pci_wakeup, NULL);
}
-static int pci_dev_wait(struct pci_dev *dev, char *reset_type, int timeout)
+static int pci_dev_get_reset_ready_poll_ms(struct pci_dev *dev)
{
+ if (dev->reset_ready_poll_ms >= 0)
+ return dev->reset_ready_poll_ms;
+
+ return pcie_reset_ready_poll_ms;
+}
+
+static int pci_dev_wait(struct pci_dev *dev, char *reset_type)
+{
+ int timeout = pci_dev_get_reset_ready_poll_ms(dev);
int delay = 1;
u32 id;
@@ -4518,7 +4527,7 @@ int pcie_flr(struct pci_dev *dev)
*/
msleep(100);
- return pci_dev_wait(dev, "FLR", pcie_reset_ready_poll_ms);
+ return pci_dev_wait(dev, "FLR");
}
EXPORT_SYMBOL_GPL(pcie_flr);
@@ -4563,7 +4572,7 @@ static int pci_af_flr(struct pci_dev *dev, int probe)
*/
msleep(100);
- return pci_dev_wait(dev, "AF_FLR", pcie_reset_ready_poll_ms);
+ return pci_dev_wait(dev, "AF_FLR");
}
/**
@@ -4608,7 +4617,7 @@ static int pci_pm_reset(struct pci_dev *dev, int probe)
pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, csr);
pci_dev_d3_sleep(dev);
- return pci_dev_wait(dev, "PM D3hot->D0", pcie_reset_ready_poll_ms);
+ return pci_dev_wait(dev, "PM D3hot->D0");
}
/**
@@ -4838,7 +4847,7 @@ int pci_bridge_secondary_bus_reset(struct pci_dev *dev)
{
pcibios_reset_secondary_bus(dev);
- return pci_dev_wait(dev, "bus reset", pcie_reset_ready_poll_ms);
+ return pci_dev_wait(dev, "bus reset");
}
EXPORT_SYMBOL_GPL(pci_bridge_secondary_bus_reset);
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 512cb4312ddd..eeb79a45d504 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -2166,6 +2166,8 @@ struct pci_dev *pci_alloc_dev(struct pci_bus *bus)
if (!dev)
return NULL;
+ dev->reset_ready_poll_ms = -1;
+
INIT_LIST_HEAD(&dev->bus_list);
dev->dev.type = &pci_dev_type;
dev->bus = pci_bus_get(bus);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 3840a541a9de..049a41b9412b 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -468,6 +468,7 @@ struct pci_dev {
size_t romlen; /* Length if not from BAR */
char *driver_override; /* Driver name to force a match */
+ int reset_ready_poll_ms;
unsigned long priv_flags; /* Private flags for the PCI driver */
};
--
2.25.1
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