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@xxxxxxxxx> --- 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 + * 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); } -- 1.7.11.7 -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html