device_shutdown() called from reboot or power_shutdown expect
all devices to be shutdown. Same is true for even ahci pci driver.
As no ahci shutdown function is implemented, the ata subsystem
always remains alive with DMA & interrupt support. File system
related calls should not be honored after device_shutdown().
So defining ahci pci driver shutdown to freeze hardware (mask
interrupt, stop DMA engine and free DMA resources).
Signed-off-by: Prabhakar Kushwaha <pkushwaha@xxxxxxxxxxx>
---
- Resending with linux-kernel@xxxxxxxxxxxxxxx in CC
- Changes for v2: Incorporated Bjorn Helgaas's comments
- Updated description
- Removed Spurious whitespace change
Adding more details:
We are seeing an issue during kexec -e where SATA hard-disk is not
getting detected in second kernel. Lots of filesystem sync calls
can be seen even after device_shutdown().
Further invastigation revealed that pci_clear_master() causing this issue.
During device_shutdown() --> pci_device_shutdown() calls
--> ahci shutdown (not defined as of now, so device is still alive)
--> pci_clear_master()
pci_clear_master() disable DMA of device. Here filesystem calls after
device_shutdown() causing the issue.
A device must implement shutdown() to stop/freeze before pcie_clear_master()
called from pci_device_shutdown(). Otherwise It can have weird effect.
Refer https://bugzilla.kernel.org/show_bug.cgi?id=63861#c24
drivers/ata/ahci.c | 7 +++++++
drivers/ata/libata-core.c | 21 +++++++++++++++++++++
include/linux/libata.h | 1 +
3 files changed, 29 insertions(+)
diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 4bfd1b14b390..11ea1aff40db 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -81,6 +81,7 @@ enum board_ids {
static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent);
static void ahci_remove_one(struct pci_dev *dev);
+static void ahci_shutdown_one(struct pci_dev *dev);
static int ahci_vt8251_hardreset(struct ata_link *link, unsigned int *class,
unsigned long deadline);
static int ahci_avn_hardreset(struct ata_link *link, unsigned int *class,
@@ -606,6 +607,7 @@ static struct pci_driver ahci_pci_driver = {
.id_table = ahci_pci_tbl,
.probe = ahci_init_one,
.remove = ahci_remove_one,
+ .shutdown = ahci_shutdown_one,
.driver = {
.pm = &ahci_pci_pm_ops,
},
@@ -1877,6 +1879,11 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
return 0;
}
+static void ahci_shutdown_one(struct pci_dev *pdev)
+{
+ ata_pci_shutdown_one(pdev);
+}
+
static void ahci_remove_one(struct pci_dev *pdev)
{
pm_runtime_get_noresume(&pdev->dev);
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 6f4ab5c5b52d..42c8728f6117 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -6767,6 +6767,26 @@ void ata_pci_remove_one(struct pci_dev *pdev)
ata_host_detach(host);
}
+void ata_pci_shutdown_one(struct pci_dev *pdev)
+{
+ struct ata_host *host = pci_get_drvdata(pdev);
+ int i;
+
+ for (i = 0; i < host->n_ports; i++) {
+ struct ata_port *ap = host->ports[i];
+
+ ap->pflags |= ATA_PFLAG_FROZEN;
+
+ /* Disable port interrupts */
+ if (ap->ops->freeze)
+ ap->ops->freeze(ap);
+
+ /* Stop the port DMA engines */
+ if (ap->ops->port_stop)
+ ap->ops->port_stop(ap);
+ }
+}
+
/* move to PCI subsystem */
int pci_test_config_bits(struct pci_dev *pdev, const struct pci_bits *bits)
{
@@ -7387,6 +7407,7 @@ EXPORT_SYMBOL_GPL(ata_timing_cycle2mode);
#ifdef CONFIG_PCI
EXPORT_SYMBOL_GPL(pci_test_config_bits);
+EXPORT_SYMBOL_GPL(ata_pci_shutdown_one);
EXPORT_SYMBOL_GPL(ata_pci_remove_one);
#ifdef CONFIG_PM
EXPORT_SYMBOL_GPL(ata_pci_device_do_suspend);
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 2dbde119721d..bff539918d82 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -1221,6 +1221,7 @@ struct pci_bits {
};
extern int pci_test_config_bits(struct pci_dev *pdev, const struct pci_bits *bits);
+extern void ata_pci_shutdown_one(struct pci_dev *pdev);
extern void ata_pci_remove_one(struct pci_dev *pdev);
#ifdef CONFIG_PM
--
2.17.1
