From mboxrd@z Thu Jan 1 00:00:00 1970 From: Igor Grinberg Subject: Re: [PATCH] usb: musb: fix context save over suspend. Date: Tue, 22 Jan 2013 11:12:54 +0200 Message-ID: <50FE5816.30703@compulab.co.il> References: <20130121202831.40a09bbc@notabene.brown> <50FD28D3.5070107@compulab.co.il> <20130122083832.7a3026c9@notabene.brown> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20130122083832.7a3026c9@notabene.brown> Sender: linux-kernel-owner@vger.kernel.org To: NeilBrown Cc: Felipe Balbi , Greg Kroah-Hartman , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, Kevin Hilman List-Id: linux-omap@vger.kernel.org -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 It looks like Kevin has a new address: Kevin Hilman On 01/21/13 23:38, NeilBrown wrote: > On Mon, 21 Jan 2013 13:38:59 +0200 Igor Grinberg > wrote: > >> -----BEGIN PGP SIGNED MESSAGE----- >> Hash: SHA1 > >> Hi Neil, > >> On 01/21/13 11:28, NeilBrown wrote: >>> >>> >>> The standard suspend sequence involves runtime_resuming >>> devices before suspending the system. >>> So just saving context in runtime_suspend and restoring it >>> in runtime resume isn't enough. We must also save in "suspend" >>> and restore in "resume". >>> >>> Without this patch, and OMAP3 system with off_mode enabled will find >>> the musb port non-functional after suspend/resume. With the patch it >>> works perfectly. > >> Hmmm... Some time ago, this has been removed in >> 5d193ce8 (usb: musb: PM: fix context save/restore in suspend/resume path) > >> Am I missing something? Or things changed and now this patch is correct? > > Hi Igor, > thanks for alerting me to that patch .... does anyone else get the feeling > that power management to too complex to be understood by a mere human? > > That commit (5d193ce8) suggests that the musb-hdrc device is an > 'omap_device', or maybe has a PM domain set to something else. > However it isn't/doesn't. dev->pm_domain is NULL. So no PM domain layer > will ever call the musb_core musb_runtime_suspend/resume. > > The parent device - musb-omap2430 - is an omap device, does have pm_domain > set, and does have its omap2430_runtime_suspend/resume called for system > suspend and so the context for that device is saved and restored. > However that doesn't help the context for musb-hdrc. > > Whether musb ever was an omap_device is beyond my archaeological skills to > determine. > > Kevin: Was musb-hdrc ever a device with a pm_domain? or was it only ever > the various possible parents that had domains? > Are you able to defend your earlier patch in today's kernel? It > certainly causes my device not to work properly. > > Thanks, > NeilBrown > > > > >>> >>> Signed-off-by: NeilBrown >>> >>> diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c >>> index fd34867..b6ccc02 100644 >>> --- a/drivers/usb/musb/musb_core.c >>> +++ b/drivers/usb/musb/musb_core.c >>> @@ -2225,6 +2225,7 @@ static int musb_suspend(struct device *dev) >>> } >>> >>> spin_unlock_irqrestore(&musb->lock, flags); >>> + musb_save_context(musb); >>> return 0; >>> } >>> >>> @@ -2234,6 +2235,8 @@ static int musb_resume_noirq(struct device *dev) >>> * unless for some reason the whole soc powered down or the USB >>> * module got reset through the PSC (vs just being disabled). >>> */ >>> + struct musb *musb = dev_to_musb(dev); >>> + musb_restore_context(musb); >>> return 0; >>> } >>> > >> - -- >> Regards, >> Igor. >> - -- Regards, Igor. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.17 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iQIcBAEBAgAGBQJQ/lgWAAoJEBDE8YO64EfacIAP/3nyXjs8QQpcD6RcNuRSLp3O veKU2grzsUOL/Eu/8TQMM7WDz5n8YlycQ6/THNGGYojjOlEimDC02wbsI4gc5j41 QC1/XGf62Nlxv6CzORzkGkUoKXtVWzgMYKddWKPEwsXMKPun/LH4ZGDp+7Rkfcmu U0k7LM1Pv487iG9pF3Bq5BPYeMxyxyFJC0PiQEK1ZE65RKWbCvInibc7p1bvZ+XX JQxf8Qx1p/kBhqWc6LLpcHT5Z3B/F+3rxEhvf8lSu5fdRPHFffcmuX7bIbC/GlTe e6mODA114mtn5YbaKCmnYExvJcpz4Nziy+8fGLJ56aAyeKI1wsOJzhWDpSKwQiIF CVtYulk5iIfaeUA4sAzvRqEu7dJuaVgm6mEeGHQjebPastYhK7vHjiEOJJ2+LQrs 698A9wMLckp4AQ75HiwXRgi5N0W528gD8piNoIA9Sh1LwyytIa5Wg7uYw14UjtLJ QIerm0v6Ay+8FbVfmpm9k0v3HkYfv0ZVTSdtIXVAE30+WKIBTn0yszxWYo6JZtvj p0NEFUNVuR3C9k/xyzkcqwJh8Q6DrleWJeHWL59xgWWKzfeDKjU/DMOuWmuVEkTO aRdAlW32VDtUeWlWz3Jz3IOWZRJQKCW2o97n/MDyxwMoRiMWcHxYw6jti6se9S7a IGZeEMCcf39fnH5o7i2q =nwGe -----END PGP SIGNATURE-----