Commit 130f4caf145c ("libata: Ensure ata_port probe has completed before
detach") may cause system freeze during suspend.
Using async_synchronize_full() in PM callbacks is wrong, since async
callbacks that are already scheduled may wait for not-yet-scheduled
callbacks, causes a circular dependency.
Instead of using big hammer like async_synchronize_full(), use async
cookie to make sure port probe are synced, without affecting other
scheduled PM callbacks.
Fixes: 130f4caf145c ("libata: Ensure ata_port probe has completed before detach")
BugLink: https://bugs.launchpad.net/bugs/1867983
Suggested-by: John Garry <john.garry@xxxxxxxxxx>
Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
---
v2:
- Sync up to cookie + 1.
- Squash the synchronization into the same loop.
drivers/ata/libata-core.c | 9 ++++-----
include/linux/libata.h | 3 +++
2 files changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index beca5f91bb4c..b6be84f2cecb 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -42,7 +42,6 @@
#include <linux/workqueue.h>
#include <linux/scatterlist.h>
#include <linux/io.h>
-#include <linux/async.h>
#include <linux/log2.h>
#include <linux/slab.h>
#include <linux/glob.h>
@@ -5778,7 +5777,7 @@ int ata_host_register(struct ata_host *host, struct scsi_host_template *sht)
/* perform each probe asynchronously */
for (i = 0; i < host->n_ports; i++) {
struct ata_port *ap = host->ports[i];
- async_schedule(async_port_probe, ap);
+ ap->cookie = async_schedule(async_port_probe, ap);
}
return 0;
@@ -5921,10 +5920,10 @@ void ata_host_detach(struct ata_host *host)
int i;
/* Ensure ata_port probe has completed */
- async_synchronize_full();
-
- for (i = 0; i < host->n_ports; i++)
+ for (i = 0; i < host->n_ports; i++) {
+ async_synchronize_cookie(host->ports[i]->cookie + 1);
ata_port_detach(host->ports[i]);
+ }
/* the host is dead now, dissociate ACPI */
ata_acpi_dissociate(host);
diff --git a/include/linux/libata.h b/include/linux/libata.h
index cffa4714bfa8..ae6dfc107ea8 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -22,6 +22,7 @@
#include <linux/acpi.h>
#include <linux/cdrom.h>
#include <linux/sched.h>
+#include <linux/async.h>
/*
* Define if arch has non-standard setup. This is a _PCI_ standard
@@ -872,6 +873,8 @@ struct ata_port {
struct timer_list fastdrain_timer;
unsigned long fastdrain_cnt;
+ async_cookie_t cookie;
+
int em_message_type;
void *private_data;
--
2.17.1
