[PATCH V2] ACPI/Battery: Retry to get Battery information if failed during probing

[PATCH V2] ACPI/Battery: Retry to get Battery information if failed during probing

[Lan Tianyu]

Some machines'(E,G Lenovo Z480) ECs are not stable during boot up
and causes battery driver fails to be loaded due to failure of getting
battery information from EC sometimes. After several retries, the
operation will work. This patch is to retry to get battery information 5
times if the first try fails.

Reported-and-tested-by: naszar <naszar@ya.ru>
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=75581
Cc: <stable@vger.kernel.org>
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
---
Change since V2:
	Change code style and add comment.

 drivers/acpi/battery.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
index e48fc98..8ed93a3 100644
--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -34,6 +34,7 @@
 #include <linux/dmi.h>
 #include <linux/slab.h>
 #include <linux/suspend.h>
+#include <linux/delay.h>
 #include <asm/unaligned.h>
 
 #ifdef CONFIG_ACPI_PROCFS_POWER
@@ -1119,7 +1120,7 @@ static struct dmi_system_id bat_dmi_table[] = {
 
 static int acpi_battery_add(struct acpi_device *device)
 {
-	int result = 0;
+	int result = 0, retry = 5;
 	struct acpi_battery *battery = NULL;
 
 	if (!device)
@@ -1135,9 +1136,20 @@ static int acpi_battery_add(struct acpi_device *device)
 	mutex_init(&battery->sysfs_lock);
 	if (acpi_has_method(battery->device->handle, "_BIX"))
 		set_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags);
-	result = acpi_battery_update(battery, false);
+
+	/*
+	 * Some machines'(E,G Lenovo Z480) ECs are not stable
+	 * during boot up and this causes battery driver fails to be
+	 * probed due to failure of getting battery information
+	 * from EC sometimes. After several retries, the operation
+	 * may work. So add retry code here and 20ms sleep between
+	 * every retries.
+	 */
+	while ((result = acpi_battery_update(battery, false)) && retry--)
+		msleep(20);
 	if (result)
 		goto fail;
+
 #ifdef CONFIG_ACPI_PROCFS_POWER
 	result = acpi_battery_add_fs(device);
 #endif
-- 
1.8.4.rc0.1.g8f6a3e5.dirty

Re: [PATCH V2] ACPI/Battery: Retry to get Battery information if failed during probing

[Rafael J. Wysocki]

On Tuesday, June 17, 2014 03:09:54 PM Lan Tianyu wrote:
> Some machines'(E,G Lenovo Z480) ECs are not stable during boot up
> and causes battery driver fails to be loaded due to failure of getting
> battery information from EC sometimes. After several retries, the
> operation will work. This patch is to retry to get battery information 5
> times if the first try fails.
> 
> Reported-and-tested-by: naszar <naszar@ya.ru>
> Reference: https://bugzilla.kernel.org/show_bug.cgi?id=75581
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
> ---
> Change since V2:
> 	Change code style and add comment.
> 
>  drivers/acpi/battery.c | 16 ++++++++++++++--
>  1 file changed, 14 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
> index e48fc98..8ed93a3 100644
> --- a/drivers/acpi/battery.c
> +++ b/drivers/acpi/battery.c
> @@ -34,6 +34,7 @@
>  #include <linux/dmi.h>
>  #include <linux/slab.h>
>  #include <linux/suspend.h>
> +#include <linux/delay.h>
>  #include <asm/unaligned.h>
>  
>  #ifdef CONFIG_ACPI_PROCFS_POWER
> @@ -1119,7 +1120,7 @@ static struct dmi_system_id bat_dmi_table[] = {
>  
>  static int acpi_battery_add(struct acpi_device *device)
>  {
> -	int result = 0;
> +	int result = 0, retry = 5;
>  	struct acpi_battery *battery = NULL;
>  
>  	if (!device)
> @@ -1135,9 +1136,20 @@ static int acpi_battery_add(struct acpi_device *device)
>  	mutex_init(&battery->sysfs_lock);
>  	if (acpi_has_method(battery->device->handle, "_BIX"))
>  		set_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags);
> -	result = acpi_battery_update(battery, false);
> +
> +	/*
> +	 * Some machines'(E,G Lenovo Z480) ECs are not stable
> +	 * during boot up and this causes battery driver fails to be
> +	 * probed due to failure of getting battery information
> +	 * from EC sometimes. After several retries, the operation
> +	 * may work. So add retry code here and 20ms sleep between
> +	 * every retries.
> +	 */
> +	while ((result = acpi_battery_update(battery, false)) && retry--)
> +		msleep(20);
>  	if (result)
>  		goto fail;

Why not to write this as

	for (;;) {
		result = acpi_battery_update(battery, false);
		if (!result)
			break;
		else if (!--retry)
			goto fail;

		msleep(20);
	}

> +
>  #ifdef CONFIG_ACPI_PROCFS_POWER
>  	result = acpi_battery_add_fs(device);
>  #endif
> 

-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.

Re: [PATCH V2] ACPI/Battery: Retry to get Battery information if failed during probing

[David Rientjes]

On Tue, 17 Jun 2014, Rafael J. Wysocki wrote:

> > diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
> > index e48fc98..8ed93a3 100644
> > --- a/drivers/acpi/battery.c
> > +++ b/drivers/acpi/battery.c
> > @@ -34,6 +34,7 @@
> >  #include <linux/dmi.h>
> >  #include <linux/slab.h>
> >  #include <linux/suspend.h>
> > +#include <linux/delay.h>
> >  #include <asm/unaligned.h>
> >  
> >  #ifdef CONFIG_ACPI_PROCFS_POWER
> > @@ -1119,7 +1120,7 @@ static struct dmi_system_id bat_dmi_table[] = {
> >  
> >  static int acpi_battery_add(struct acpi_device *device)
> >  {
> > -	int result = 0;
> > +	int result = 0, retry = 5;
> >  	struct acpi_battery *battery = NULL;
> >  
> >  	if (!device)
> > @@ -1135,9 +1136,20 @@ static int acpi_battery_add(struct acpi_device *device)
> >  	mutex_init(&battery->sysfs_lock);
> >  	if (acpi_has_method(battery->device->handle, "_BIX"))
> >  		set_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags);
> > -	result = acpi_battery_update(battery, false);
> > +
> > +	/*
> > +	 * Some machines'(E,G Lenovo Z480) ECs are not stable
> > +	 * during boot up and this causes battery driver fails to be
> > +	 * probed due to failure of getting battery information
> > +	 * from EC sometimes. After several retries, the operation
> > +	 * may work. So add retry code here and 20ms sleep between
> > +	 * every retries.
> > +	 */
> > +	while ((result = acpi_battery_update(battery, false)) && retry--)
> > +		msleep(20);
> >  	if (result)
> >  		goto fail;
> 
> Why not to write this as
> 
> 	for (;;) {
> 		result = acpi_battery_update(battery, false);
> 		if (!result)
> 			break;
> 		else if (!--retry)
> 			goto fail;
> 
> 		msleep(20);
> 	}
> 

I suggested a similar for loop earlier, I think it's cleaner.

Re: [PATCH V2] ACPI/Battery: Retry to get Battery information if failed during probing

[Rafael J. Wysocki]

On Wednesday, June 18, 2014 03:15:47 PM David Rientjes wrote:
> On Tue, 17 Jun 2014, Rafael J. Wysocki wrote:
> 
> > > diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
> > > index e48fc98..8ed93a3 100644
> > > --- a/drivers/acpi/battery.c
> > > +++ b/drivers/acpi/battery.c
> > > @@ -34,6 +34,7 @@
> > >  #include <linux/dmi.h>
> > >  #include <linux/slab.h>
> > >  #include <linux/suspend.h>
> > > +#include <linux/delay.h>
> > >  #include <asm/unaligned.h>
> > >  
> > >  #ifdef CONFIG_ACPI_PROCFS_POWER
> > > @@ -1119,7 +1120,7 @@ static struct dmi_system_id bat_dmi_table[] = {
> > >  
> > >  static int acpi_battery_add(struct acpi_device *device)
> > >  {
> > > -	int result = 0;
> > > +	int result = 0, retry = 5;
> > >  	struct acpi_battery *battery = NULL;
> > >  
> > >  	if (!device)
> > > @@ -1135,9 +1136,20 @@ static int acpi_battery_add(struct acpi_device *device)
> > >  	mutex_init(&battery->sysfs_lock);
> > >  	if (acpi_has_method(battery->device->handle, "_BIX"))
> > >  		set_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags);
> > > -	result = acpi_battery_update(battery, false);
> > > +
> > > +	/*
> > > +	 * Some machines'(E,G Lenovo Z480) ECs are not stable
> > > +	 * during boot up and this causes battery driver fails to be
> > > +	 * probed due to failure of getting battery information
> > > +	 * from EC sometimes. After several retries, the operation
> > > +	 * may work. So add retry code here and 20ms sleep between
> > > +	 * every retries.
> > > +	 */
> > > +	while ((result = acpi_battery_update(battery, false)) && retry--)
> > > +		msleep(20);
> > >  	if (result)
> > >  		goto fail;
> > 
> > Why not to write this as
> > 
> > 	for (;;) {
> > 		result = acpi_battery_update(battery, false);
> > 		if (!result)
> > 			break;
> > 		else if (!--retry)
> > 			goto fail;
> > 
> > 		msleep(20);
> > 	}
> > 
> 
> I suggested a similar for loop earlier, I think it's cleaner.

Precisely.  And it would be even more clean to introduce

static bool acpi_battery_update_retry(struct acpi_battery *battery)
{
	int retry, ret;

	for (retry = 5; retry; retry--) {
		ret = acpi_battery_update(battery, false);
		if (!ret)
			break;

		msleep(20);
	}
	return ret;
}

and use that instead of the open-coded loop.

Rafael

Re: [PATCH V2] ACPI/Battery: Retry to get Battery information if failed during probing

[Lan Tianyu]

On 2014年06月19日 07:00, Rafael J. Wysocki wrote:
> On Wednesday, June 18, 2014 03:15:47 PM David Rientjes wrote:
>> On Tue, 17 Jun 2014, Rafael J. Wysocki wrote:
>>
>>>> diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
>>>> index e48fc98..8ed93a3 100644
>>>> --- a/drivers/acpi/battery.c
>>>> +++ b/drivers/acpi/battery.c
>>>> @@ -34,6 +34,7 @@
>>>>  #include <linux/dmi.h>
>>>>  #include <linux/slab.h>
>>>>  #include <linux/suspend.h>
>>>> +#include <linux/delay.h>
>>>>  #include <asm/unaligned.h>
>>>>  
>>>>  #ifdef CONFIG_ACPI_PROCFS_POWER
>>>> @@ -1119,7 +1120,7 @@ static struct dmi_system_id bat_dmi_table[] = {
>>>>  
>>>>  static int acpi_battery_add(struct acpi_device *device)
>>>>  {
>>>> -	int result = 0;
>>>> +	int result = 0, retry = 5;
>>>>  	struct acpi_battery *battery = NULL;
>>>>  
>>>>  	if (!device)
>>>> @@ -1135,9 +1136,20 @@ static int acpi_battery_add(struct acpi_device *device)
>>>>  	mutex_init(&battery->sysfs_lock);
>>>>  	if (acpi_has_method(battery->device->handle, "_BIX"))
>>>>  		set_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags);
>>>> -	result = acpi_battery_update(battery, false);
>>>> +
>>>> +	/*
>>>> +	 * Some machines'(E,G Lenovo Z480) ECs are not stable
>>>> +	 * during boot up and this causes battery driver fails to be
>>>> +	 * probed due to failure of getting battery information
>>>> +	 * from EC sometimes. After several retries, the operation
>>>> +	 * may work. So add retry code here and 20ms sleep between
>>>> +	 * every retries.
>>>> +	 */
>>>> +	while ((result = acpi_battery_update(battery, false)) && retry--)
>>>> +		msleep(20);
>>>>  	if (result)
>>>>  		goto fail;
>>>
>>> Why not to write this as
>>>
>>> 	for (;;) {
>>> 		result = acpi_battery_update(battery, false);
>>> 		if (!result)
>>> 			break;
>>> 		else if (!--retry)
>>> 			goto fail;
>>>
>>> 		msleep(20);
>>> 	}
>>>
>>
>> I suggested a similar for loop earlier, I think it's cleaner.
> 
> Precisely.  And it would be even more clean to introduce
> 
> static bool acpi_battery_update_retry(struct acpi_battery *battery)
> {
> 	int retry, ret;
> 
> 	for (retry = 5; retry; retry--) {
> 		ret = acpi_battery_update(battery, false);
> 		if (!ret)
> 			break;
> 
> 		msleep(20);
> 	}
> 	return ret;
> }
> 
> and use that instead of the open-coded loop.

Ok. I will update patch like this.

> 
> Rafael
> 


-- 
Best regards
Tianyu Lan
--
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