From bc6e7c4b0d1a1f742d96556f63d68f17f4e232c3 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Fri, 14 Mar 2014 13:52:48 -0700 Subject: libata, libsas: kill pm_result and related cleanup Tejun says: "At least for libata, worrying about suspend/resume failures don't make whole lot of sense. If suspend failed, just proceed with suspend. If the device can't be woken up afterwards, that's that. There isn't anything we could have done differently anyway. The same for resume, if spinup fails, the device is dud and the following commands will invoke EH actions and will eventually fail. Again, there really isn't any *choice* to make. Just making sure the errors are handled gracefully (ie. don't crash) and the following commands are handled correctly should be enough." The only libata user that actually cares about the result from a suspend operation is libsas. However, it only cares about whether queuing a new operation collides with an in-flight one. All libsas does with the error is retry, but we can just let libata wait for the previous operation before continuing. Other cleanups include: 1/ Unifying all ata port pm operations on an ata_port_pm_ prefix 2/ Marking all ata port pm helper routines as returning void, only ata_port_pm_ entry points need to fake a 0 return value. 3/ Killing ata_port_{suspend|resume}_common() in favor of calling ata_port_request_pm() directly 4/ Killing the wrappers that just do a to_ata_port() conversion 5/ Clearly marking the entry points that do async operations with an _async suffix. Reference: http://marc.info/?l=linux-scsi&m=138995409532286&w=2 Cc: Phillip Susi Cc: Alan Stern Suggested-by: Tejun Heo Signed-off-by: Todd Brandt Signed-off-by: Dan Williams Signed-off-by: Tejun Heo --- drivers/ata/libata-core.c | 135 +++++++++++++++++++++------------------------- 1 file changed, 60 insertions(+), 75 deletions(-) (limited to 'drivers/ata/libata-core.c') diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index 1a3dbd1b196e..66110ed2c1c0 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -5351,22 +5351,17 @@ bool ata_link_offline(struct ata_link *link) } #ifdef CONFIG_PM -static int ata_port_request_pm(struct ata_port *ap, pm_message_t mesg, - unsigned int action, unsigned int ehi_flags, - int *async) +static void ata_port_request_pm(struct ata_port *ap, pm_message_t mesg, + unsigned int action, unsigned int ehi_flags, + bool async) { struct ata_link *link; unsigned long flags; - int rc = 0; /* Previous resume operation might still be in * progress. Wait for PM_PENDING to clear. */ if (ap->pflags & ATA_PFLAG_PM_PENDING) { - if (async) { - *async = -EAGAIN; - return 0; - } ata_port_wait_eh(ap); WARN_ON(ap->pflags & ATA_PFLAG_PM_PENDING); } @@ -5375,11 +5370,6 @@ static int ata_port_request_pm(struct ata_port *ap, pm_message_t mesg, spin_lock_irqsave(ap->lock, flags); ap->pm_mesg = mesg; - if (async) - ap->pm_result = async; - else - ap->pm_result = &rc; - ap->pflags |= ATA_PFLAG_PM_PENDING; ata_for_each_link(link, ap, HOST_FIRST) { link->eh_info.action |= action; @@ -5390,87 +5380,81 @@ static int ata_port_request_pm(struct ata_port *ap, pm_message_t mesg, spin_unlock_irqrestore(ap->lock, flags); - /* wait and check result */ if (!async) { ata_port_wait_eh(ap); WARN_ON(ap->pflags & ATA_PFLAG_PM_PENDING); } - - return rc; } -static int __ata_port_suspend_common(struct ata_port *ap, pm_message_t mesg, int *async) +/* + * On some hardware, device fails to respond after spun down for suspend. As + * the device won't be used before being resumed, we don't need to touch the + * device. Ask EH to skip the usual stuff and proceed directly to suspend. + * + * http://thread.gmane.org/gmane.linux.ide/46764 + */ +static const unsigned int ata_port_suspend_ehi = ATA_EHI_QUIET + | ATA_EHI_NO_AUTOPSY + | ATA_EHI_NO_RECOVERY; + +static void ata_port_suspend(struct ata_port *ap, pm_message_t mesg) { - /* - * On some hardware, device fails to respond after spun down - * for suspend. As the device won't be used before being - * resumed, we don't need to touch the device. Ask EH to skip - * the usual stuff and proceed directly to suspend. - * - * http://thread.gmane.org/gmane.linux.ide/46764 - */ - unsigned int ehi_flags = ATA_EHI_QUIET | ATA_EHI_NO_AUTOPSY | - ATA_EHI_NO_RECOVERY; - return ata_port_request_pm(ap, mesg, 0, ehi_flags, async); + ata_port_request_pm(ap, mesg, 0, ata_port_suspend_ehi, false); } -static int ata_port_suspend_common(struct device *dev, pm_message_t mesg) +static void ata_port_suspend_async(struct ata_port *ap, pm_message_t mesg) { - struct ata_port *ap = to_ata_port(dev); - - return __ata_port_suspend_common(ap, mesg, NULL); + ata_port_request_pm(ap, mesg, 0, ata_port_suspend_ehi, true); } -static int ata_port_suspend(struct device *dev) +static int ata_port_pm_suspend(struct device *dev) { + struct ata_port *ap = to_ata_port(dev); + if (pm_runtime_suspended(dev)) return 0; - return ata_port_suspend_common(dev, PMSG_SUSPEND); + ata_port_suspend(ap, PMSG_SUSPEND); + return 0; } -static int ata_port_do_freeze(struct device *dev) +static int ata_port_pm_freeze(struct device *dev) { + struct ata_port *ap = to_ata_port(dev); + if (pm_runtime_suspended(dev)) return 0; - return ata_port_suspend_common(dev, PMSG_FREEZE); + ata_port_suspend(ap, PMSG_FREEZE); + return 0; } -static int ata_port_poweroff(struct device *dev) +static int ata_port_pm_poweroff(struct device *dev) { - return ata_port_suspend_common(dev, PMSG_HIBERNATE); + ata_port_suspend(to_ata_port(dev), PMSG_HIBERNATE); + return 0; } -static int __ata_port_resume_common(struct ata_port *ap, pm_message_t mesg, - int *async) -{ - int rc; +static const unsigned int ata_port_resume_ehi = ATA_EHI_NO_AUTOPSY + | ATA_EHI_QUIET; - rc = ata_port_request_pm(ap, mesg, ATA_EH_RESET, - ATA_EHI_NO_AUTOPSY | ATA_EHI_QUIET, async); - return rc; +static void ata_port_resume(struct ata_port *ap, pm_message_t mesg) +{ + ata_port_request_pm(ap, mesg, ATA_EH_RESET, ata_port_resume_ehi, false); } -static int ata_port_resume_common(struct device *dev, pm_message_t mesg) +static void ata_port_resume_async(struct ata_port *ap, pm_message_t mesg) { - struct ata_port *ap = to_ata_port(dev); - - return __ata_port_resume_common(ap, mesg, NULL); + ata_port_request_pm(ap, mesg, ATA_EH_RESET, ata_port_resume_ehi, true); } -static int ata_port_resume(struct device *dev) +static int ata_port_pm_resume(struct device *dev) { - int rc; - - rc = ata_port_resume_common(dev, PMSG_RESUME); - if (!rc) { - pm_runtime_disable(dev); - pm_runtime_set_active(dev); - pm_runtime_enable(dev); - } - - return rc; + ata_port_resume(to_ata_port(dev), PMSG_RESUME); + pm_runtime_disable(dev); + pm_runtime_set_active(dev); + pm_runtime_enable(dev); + return 0; } /* @@ -5499,21 +5483,23 @@ static int ata_port_runtime_idle(struct device *dev) static int ata_port_runtime_suspend(struct device *dev) { - return ata_port_suspend_common(dev, PMSG_AUTO_SUSPEND); + ata_port_suspend(to_ata_port(dev), PMSG_AUTO_SUSPEND); + return 0; } static int ata_port_runtime_resume(struct device *dev) { - return ata_port_resume_common(dev, PMSG_AUTO_RESUME); + ata_port_resume(to_ata_port(dev), PMSG_AUTO_RESUME); + return 0; } static const struct dev_pm_ops ata_port_pm_ops = { - .suspend = ata_port_suspend, - .resume = ata_port_resume, - .freeze = ata_port_do_freeze, - .thaw = ata_port_resume, - .poweroff = ata_port_poweroff, - .restore = ata_port_resume, + .suspend = ata_port_pm_suspend, + .resume = ata_port_pm_resume, + .freeze = ata_port_pm_freeze, + .thaw = ata_port_pm_resume, + .poweroff = ata_port_pm_poweroff, + .restore = ata_port_pm_resume, .runtime_suspend = ata_port_runtime_suspend, .runtime_resume = ata_port_runtime_resume, @@ -5525,18 +5511,17 @@ static const struct dev_pm_ops ata_port_pm_ops = { * level. sas suspend/resume is async to allow parallel port recovery * since sas has multiple ata_port instances per Scsi_Host. */ -int ata_sas_port_async_suspend(struct ata_port *ap, int *async) +void ata_sas_port_suspend(struct ata_port *ap) { - return __ata_port_suspend_common(ap, PMSG_SUSPEND, async); + ata_port_suspend_async(ap, PMSG_SUSPEND); } -EXPORT_SYMBOL_GPL(ata_sas_port_async_suspend); +EXPORT_SYMBOL_GPL(ata_sas_port_suspend); -int ata_sas_port_async_resume(struct ata_port *ap, int *async) +void ata_sas_port_resume(struct ata_port *ap) { - return __ata_port_resume_common(ap, PMSG_RESUME, async); + ata_port_resume_async(ap, PMSG_RESUME); } -EXPORT_SYMBOL_GPL(ata_sas_port_async_resume); - +EXPORT_SYMBOL_GPL(ata_sas_port_resume); /** * ata_host_suspend - suspend host -- cgit From 200421a80f6e0a9e39d698944cc35cba103eb6ce Mon Sep 17 00:00:00 2001 From: Todd Brandt Date: Fri, 14 Mar 2014 13:52:54 -0700 Subject: libata: async resume Improve overall system resume time by making libata link recovery actions asynchronous relative to other resume events. Link resume operations are performed using the scsi_eh thread, so commands, particularly the sd resume start/stop command, will be held off until the device exits error handling. Libata already flushes eh with ata_port_wait_eh() in the port teardown paths, so there are no concerns with async operation colliding with the end-of-life of the ata_port object. Also, libata-core is already careful to flush in-flight pm operations before another round of pm starts on the given ata_port. Reference: https://01.org/suspendresume/blogs/tebrandt/2013/hard-disk-resume-optimization-simpler-approach Cc: Len Brown Cc: Phillip Susi Cc: Alan Stern Signed-off-by: Todd Brandt [djbw: rebase on cleanup patch, changelog wordsmithing] Signed-off-by: Dan Williams Signed-off-by: Tejun Heo --- drivers/ata/libata-core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/ata/libata-core.c') diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index 66110ed2c1c0..c37eb02c7136 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -5450,7 +5450,7 @@ static void ata_port_resume_async(struct ata_port *ap, pm_message_t mesg) static int ata_port_pm_resume(struct device *dev) { - ata_port_resume(to_ata_port(dev), PMSG_RESUME); + ata_port_resume_async(to_ata_port(dev), PMSG_RESUME); pm_runtime_disable(dev); pm_runtime_set_active(dev); pm_runtime_enable(dev); -- cgit