Patchwork [v11,9/9] libata: do not suspend port if normal ODD is attached

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Submitter Aaron Lu
Date Jan. 6, 2013, 2:48 a.m.
Message ID <1357440509-28108-10-git-send-email-aaron.lu@intel.com>
Download mbox | patch
Permalink /patch/209721/
State Not Applicable
Delegated to: David Miller
Headers show

Comments

Aaron Lu - Jan. 6, 2013, 2:48 a.m.
For ODDs, the upper layer will poll for media change every a few
seconds, which will make it enter and leave suspend state very
oftern. And as each suspend will also cause a hard/soft reset,
the gain of runtime suspend is very little while the ODD may
mis-function after constantly being reset. So the idle callback
here will not proceed to suspend if a non-ZPODD capable ODD is
attached to the port.

Signed-off-by: Aaron Lu <aaron.lu@intel.com>
---
 drivers/ata/libata-core.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
Sergei Shtylyov - Jan. 6, 2013, 2:34 p.m.
Hello.

On 06-01-2013 6:48, Aaron Lu wrote:

> For ODDs, the upper layer will poll for media change every a few
> seconds, which will make it enter and leave suspend state very
> oftern. And as each suspend will also cause a hard/soft reset,

    s/oftern/often/

> the gain of runtime suspend is very little while the ODD may
> mis-function after constantly being reset. So the idle callback
> here will not proceed to suspend if a non-ZPODD capable ODD is
> attached to the port.

> Signed-off-by: Aaron Lu <aaron.lu@intel.com>
> ---
>   drivers/ata/libata-core.c | 19 +++++++++++++++++++
>   1 file changed, 19 insertions(+)

> diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
> index 65a362e..f664a90 100644
> --- a/drivers/ata/libata-core.c
> +++ b/drivers/ata/libata-core.c
> @@ -5408,8 +5408,27 @@ static int ata_port_resume(struct device *dev)
>   	return rc;
>   }
>
> +/*
> + * For ODDs, the upper layer will poll for media change every a few seconds,
> + * which will make it enter and leave suspend state every a few seconds. And

    Article is not needed before "few". (Same comment to the changelog.)

> + * as each suspend will cause a hard/soft reset, the gain of runtime suspend
> + * is very little and the ODD may mis-function after constantly being reset.

    s/mis-function/malfunction/ perhaps? (Same in the changelog.)

MBR, Sergei

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Aaron Lu - Jan. 7, 2013, 1:09 a.m.
Hi Sergei,

Thanks for reviewing, will update in next revision.

-Aaron

On 01/06/2013 10:34 PM, Sergei Shtylyov wrote:
> Hello.
> 
> On 06-01-2013 6:48, Aaron Lu wrote:
> 
>> For ODDs, the upper layer will poll for media change every a few
>> seconds, which will make it enter and leave suspend state very
>> oftern. And as each suspend will also cause a hard/soft reset,
> 
>     s/oftern/often/
> 
>> the gain of runtime suspend is very little while the ODD may
>> mis-function after constantly being reset. So the idle callback
>> here will not proceed to suspend if a non-ZPODD capable ODD is
>> attached to the port.
> 
>> Signed-off-by: Aaron Lu <aaron.lu@intel.com>
>> ---
>>   drivers/ata/libata-core.c | 19 +++++++++++++++++++
>>   1 file changed, 19 insertions(+)
> 
>> diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
>> index 65a362e..f664a90 100644
>> --- a/drivers/ata/libata-core.c
>> +++ b/drivers/ata/libata-core.c
>> @@ -5408,8 +5408,27 @@ static int ata_port_resume(struct device *dev)
>>   	return rc;
>>   }
>>
>> +/*
>> + * For ODDs, the upper layer will poll for media change every a few seconds,
>> + * which will make it enter and leave suspend state every a few seconds. And
> 
>     Article is not needed before "few". (Same comment to the changelog.)
> 
>> + * as each suspend will cause a hard/soft reset, the gain of runtime suspend
>> + * is very little and the ODD may mis-function after constantly being reset.
> 
>     s/mis-function/malfunction/ perhaps? (Same in the changelog.)
> 
> MBR, Sergei
> 

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Patch

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 65a362e..f664a90 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -5408,8 +5408,27 @@  static int ata_port_resume(struct device *dev)
 	return rc;
 }
 
+/*
+ * For ODDs, the upper layer will poll for media change every a few seconds,
+ * which will make it enter and leave suspend state every a few seconds. And
+ * as each suspend will cause a hard/soft reset, the gain of runtime suspend
+ * is very little and the ODD may mis-function after constantly being reset.
+ * So the idle callback here will not proceed to suspend if a non-ZPODD capable
+ * ODD is attached to the port.
+ */
 static int ata_port_runtime_idle(struct device *dev)
 {
+	struct ata_port *ap = to_ata_port(dev);
+	struct ata_link *link;
+	struct ata_device *adev;
+
+	ata_for_each_link(link, ap, HOST_FIRST) {
+		ata_for_each_dev(adev, link, ENABLED)
+			if (adev->class == ATA_DEV_ATAPI &&
+			    !zpodd_dev_enabled(adev))
+				return -EBUSY;
+	}
+
 	return pm_runtime_suspend(dev);
 }