diff options
| author | Khalid Aziz <khalid.aziz@oracle.com> | 2013-11-27 15:19:25 -0700 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2013-12-07 14:20:28 -0700 |
| commit | 4fc9bbf98fd66f879e628d8537ba7c240be2b58e (patch) | |
| tree | 09cdc49f0f145f7af3380c7896fa539d4192ca1d | |
| parent | f407dae76040c9529c2c83b1488dda4ffc54522c (diff) | |
PCI: Disable Bus Master only on kexec reboot
Add a flag to tell the PCI subsystem that kernel is shutting down in
preparation to kexec a kernel. Add code in PCI subsystem to use this flag
to clear Bus Master bit on PCI devices only in case of kexec reboot.
This fixes a power-off problem on Acer Aspire V5-573G and likely other
machines and avoids any other issues caused by clearing Bus Master bit on
PCI devices in normal shutdown path. The problem was introduced by
b566a22c2332 ("PCI: disable Bus Master on PCI device shutdown").
This patch is based on discussion at
http://marc.info/?l=linux-pci&m=138425645204355&w=2
Link: https://bugzilla.kernel.org/show_bug.cgi?id=63861
Reported-by: Chang Liu <cl91tp@gmail.com>
Signed-off-by: Khalid Aziz <khalid.aziz@oracle.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: stable@vger.kernel.org # v3.5+
| -rw-r--r-- | drivers/pci/pci-driver.c | 12 | ||||
| -rw-r--r-- | include/linux/kexec.h | 3 | ||||
| -rw-r--r-- | kernel/kexec.c | 4 |
3 files changed, 16 insertions, 3 deletions
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index 7edd5c30744..25f0bc65916 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -19,6 +19,7 @@ #include <linux/cpu.h> #include <linux/pm_runtime.h> #include <linux/suspend.h> +#include <linux/kexec.h> #include "pci.h" struct pci_dynid { @@ -415,12 +416,17 @@ static void pci_device_shutdown(struct device *dev) pci_msi_shutdown(pci_dev); pci_msix_shutdown(pci_dev); +#ifdef CONFIG_KEXEC /* - * 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 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 (pci_dev->current_state <= PCI_D3hot) + if (kexec_in_progress && (pci_dev->current_state <= PCI_D3hot)) pci_clear_master(pci_dev); +#endif } #ifdef CONFIG_PM diff --git a/include/linux/kexec.h b/include/linux/kexec.h index d78d28a733b..5fd33dc1fe3 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -198,6 +198,9 @@ extern u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4]; extern size_t vmcoreinfo_size; extern size_t vmcoreinfo_max_size; +/* flag to track if kexec reboot is in progress */ +extern bool kexec_in_progress; + int __init parse_crashkernel(char *cmdline, unsigned long long system_ram, unsigned long long *crash_size, unsigned long long *crash_base); int parse_crashkernel_high(char *cmdline, unsigned long long system_ram, diff --git a/kernel/kexec.c b/kernel/kexec.c index 490afc03627..d0d8fca5406 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -47,6 +47,9 @@ u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4]; size_t vmcoreinfo_size; size_t vmcoreinfo_max_size = sizeof(vmcoreinfo_data); +/* Flag to indicate we are going to kexec a new kernel */ +bool kexec_in_progress = false; + /* Location of the reserved area for the crash kernel */ struct resource crashk_res = { .name = "Crash kernel", @@ -1675,6 +1678,7 @@ int kernel_kexec(void) } else #endif { + kexec_in_progress = true; kernel_restart_prepare(NULL); printk(KERN_EMERG "Starting new kernel\n"); machine_shutdown(); |