[Intel-gfx] [PATCH v2] PCI / PM: tune down RPM suspend error message with EBUSY and EAGAIN retval

[Imre Deak]

The runtime PM core doesn't treat EBUSY and EAGAIN retvals from the driver
suspend hooks as errors, but they still show up as errors in dmesg. Tune
them down.

One problem caused by this was noticed by Daniel: the i915 driver
returns EAGAIN to signal a temporary failure to suspend and as a request
towards the RPM core for scheduling a suspend again. This is a normal
event, but the resulting error message flags a breakage during the
driver's automated testing which parses dmesg and picks up the error.

v2:
- fix compile breake when CONFIG_PM_SLEEP=n (0-day builder)

Reported-by: Daniel Vetter <daniel.vetter at intel.com>
Signed-off-by: Imre Deak <imre.deak at intel.com>
---
 drivers/base/power/main.c |  7 +++++--
 drivers/pci/pci-driver.c  |  2 +-
 include/linux/pm.h        | 11 +++++++++--
 3 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index 1710c26..39d2090 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -1679,9 +1679,12 @@ int dpm_suspend_start(pm_message_t state)
 }
 EXPORT_SYMBOL_GPL(dpm_suspend_start);
 
-void __suspend_report_result(const char *function, void *fn, int ret)
+void __suspend_report_result(const char *function, void *fn, int ret,
+			     bool runtime_pm)
 {
-	if (ret)
+	if (runtime_pm && (ret == -EBUSY || ret == -EAGAIN))
+		printk(KERN_DEBUG "%s(): %pF returns %d\n", function, fn, ret);
+	else if (ret)
 		printk(KERN_ERR "%s(): %pF returns %d\n", function, fn, ret);
 }
 EXPORT_SYMBOL_GPL(__suspend_report_result);
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index 108a311..9569572 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -1142,7 +1142,7 @@ static int pci_pm_runtime_suspend(struct device *dev)
 	pci_dev->state_saved = false;
 	pci_dev->no_d3cold = false;
 	error = pm->runtime_suspend(dev);
-	suspend_report_result(pm->runtime_suspend, error);
+	rpm_suspend_report_result(pm->runtime_suspend, error);
 	if (error)
 		return error;
 	if (!pci_dev->d3cold_allowed)
diff --git a/include/linux/pm.h b/include/linux/pm.h
index 35d599e..54f37e3 100644
--- a/include/linux/pm.h
+++ b/include/linux/pm.h
@@ -702,11 +702,17 @@ extern int dpm_suspend_late(pm_message_t state);
 extern int dpm_suspend(pm_message_t state);
 extern int dpm_prepare(pm_message_t state);
 
-extern void __suspend_report_result(const char *function, void *fn, int ret);
+extern void __suspend_report_result(const char *function, void *fn, int ret,
+				    bool runtime_pm);
 
 #define suspend_report_result(fn, ret)					\
 	do {								\
-		__suspend_report_result(__func__, fn, ret);		\
+		__suspend_report_result(__func__, fn, ret, false);	\
+	} while (0)
+
+#define rpm_suspend_report_result(fn, ret)				\
+	do {								\
+		__suspend_report_result(__func__, fn, ret, true);	\
 	} while (0)
 
 extern int device_pm_wait_for_dev(struct device *sub, struct device *dev);
@@ -744,6 +750,7 @@ static inline int dpm_suspend_start(pm_message_t state)
 }
 
 #define suspend_report_result(fn, ret)		do {} while (0)
+#define rpm_suspend_report_result(fn, ret)	do {} while (0)
 
 static inline int device_pm_wait_for_dev(struct device *a, struct device *b)
 {
-- 
2.5.0