After commit 745be2e700cd ("PCIe: portdrv: call pci_disable_device
during remove") and commit cc27b735ad3a ("PCI/portdrv: Turn off PCIe
services during shutdown"), it also calls pci_disable_device() during
shutdown, this leads to shutdown or reboot failure occasionally due to
clear PCI_COMMAND_MASTER on the device in do_pci_disable_device().
drivers/pci/pci.c
static void do_pci_disable_device(struct pci_dev *dev)
{
u16 pci_command;
pci_read_config_word(dev, PCI_COMMAND, &pci_command);
if (pci_command & PCI_COMMAND_MASTER) {
pci_command &= ~PCI_COMMAND_MASTER;
pci_write_config_word(dev, PCI_COMMAND, pci_command);
}
pcibios_disable_device(dev);
}
When remove "pci_command &= ~PCI_COMMAND_MASTER;", it can work well.
As Oliver O'Halloran said, no need to call pci_disable_device() when
actually shutting down, but we should call pci_disable_device() before
handing over to the new kernel on kexec reboot, so we can do some
condition checks which are similar with pci_device_shutdown(), this is
done by commit 4fc9bbf98fd6 ("PCI: Disable Bus Master only on kexec
reboot") and commit 6e0eda3c3898 ("PCI: Don't try to disable Bus Master
on disconnected PCI devices").
drivers/pci/pci-driver.c
static void pci_device_shutdown(struct device *dev)
{
...
/*
* If this is a kexec reboot, turn off Bus Master bit on the
* device to tell it to not continue to do DMA. Don't touch
* devices in D3cold or unknown states.
* If it is not a kexec reboot, firmware will hit the PCI
* devices with big hammer and stop their DMA any way.
*/
if (kexec_in_progress && (pci_dev->current_state <= PCI_D3hot))
pci_clear_master(pci_dev);
}
Signed-off-by: Tiezhu Yang <yangtie...@loongson.cn>
---
drivers/pci/pcie/portdrv_core.c | 1 -
drivers/pci/pcie/portdrv_pci.c | 25 ++++++++++++++++++++++++-
2 files changed, 24 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
index 50a9522..1991aca 100644
--- a/drivers/pci/pcie/portdrv_core.c
+++ b/drivers/pci/pcie/portdrv_core.c
@@ -491,7 +491,6 @@ void pcie_port_device_remove(struct pci_dev *dev)
{
device_for_each_child(&dev->dev, NULL, remove_iter);
pci_free_irq_vectors(dev);
- pci_disable_device(dev);
}
/**
diff --git a/drivers/pci/pcie/portdrv_pci.c b/drivers/pci/pcie/portdrv_pci.c
index 3a3ce40..ce89a9e8 100644
--- a/drivers/pci/pcie/portdrv_pci.c
+++ b/drivers/pci/pcie/portdrv_pci.c
@@ -15,6 +15,7 @@
#include <linux/init.h>
#include <linux/aer.h>
#include <linux/dmi.h>
+#include <linux/kexec.h>
#include "../pci.h"
#include "portdrv.h"
@@ -143,6 +144,28 @@ static void pcie_portdrv_remove(struct pci_dev *dev)
}
pcie_port_device_remove(dev);
+ pci_disable_device(dev);
+}
+
+static void pcie_portdrv_shutdown(struct pci_dev *dev)
+{
+ if (pci_bridge_d3_possible(dev)) {
+ pm_runtime_forbid(&dev->dev);
+ pm_runtime_get_noresume(&dev->dev);
+ pm_runtime_dont_use_autosuspend(&dev->dev);
+ }
+
+ pcie_port_device_remove(dev);
+
+ /*
+ * If this is a kexec reboot, turn off Bus Master bit on the
+ * device to tell it to not continue to do DMA. Don't touch
+ * devices in D3cold or unknown states.
+ * If it is not a kexec reboot, firmware will hit the PCI
+ * devices with big hammer and stop their DMA any way.
+ */
+ if (kexec_in_progress && (dev->current_state <= PCI_D3hot))
+ pci_disable_device(dev);
}
static pci_ers_result_t pcie_portdrv_error_detected(struct pci_dev *dev,
@@ -211,7 +234,7 @@ static void pcie_portdrv_err_resume(struct pci_dev *dev)
.probe = pcie_portdrv_probe,
.remove = pcie_portdrv_remove,
- .shutdown = pcie_portdrv_remove,
+ .shutdown = pcie_portdrv_shutdown,
.err_handler = &pcie_portdrv_err_handler,
--
1.8.3.1
