From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andreas Kemnade Subject: Re: [PATCH RESEND] phy: phy-twl4030-usb: fix denied runtime access Date: Mon, 17 Sep 2018 20:56:34 +0200 Message-ID: <20180917205634.6a320cad@aktux> References: <20180917052254.12336-1-andreas@kemnade.info> <20180917175131.GA104770@dtor-ws> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; boundary="Sig_/_BaF6VuUb2T=xBhucJeMtCQ"; protocol="application/pgp-signature" Return-path: In-Reply-To: <20180917175131.GA104770@dtor-ws> Sender: linux-kernel-owner@vger.kernel.org To: Dmitry Torokhov Cc: kishon@ti.com, lee.jones@linaro.org, daniel.thompson@linaro.org, wsa@the-dreams.de, linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org, Discussions about the Letux Kernel List-Id: linux-omap@vger.kernel.org --Sig_/_BaF6VuUb2T=xBhucJeMtCQ Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable Hi Dmitry, On Mon, 17 Sep 2018 10:51:31 -0700 Dmitry Torokhov wrote: > Hi Andreas, >=20 > On Mon, Sep 17, 2018 at 07:22:54AM +0200, Andreas Kemnade wrote: > > When runtime is not enabled, pm_runtime_get_sync() returns -EACCESS, > > the counter will be incremented but the resume callback not called, > > so enumeration and charging will not start properly. > > To avoid that happen, wait and try again later. > >=20 > > Practically this happens when the device is woken up from suspend by > > plugging in usb. > >=20 > > Signed-off-by: Andreas Kemnade > > --- > > drivers/phy/ti/phy-twl4030-usb.c | 9 +++++++++ > > 1 file changed, 9 insertions(+) > >=20 > > diff --git a/drivers/phy/ti/phy-twl4030-usb.c b/drivers/phy/ti/phy-twl4= 030-usb.c > > index a44680d64f9b..1f3cf4e48383 100644 > > --- a/drivers/phy/ti/phy-twl4030-usb.c > > +++ b/drivers/phy/ti/phy-twl4030-usb.c > > @@ -552,6 +552,15 @@ static irqreturn_t twl4030_usb_irq(int irq, void *= _twl) > > =20 > > status =3D twl4030_usb_linkstat(twl); > > =20 > > + /* we might get here too early when runtime is not ready yet > > + * and we will get an EACCESS later, so try again later > > + */ =20 >=20 > How exactly can this happen? What disables (and later re-enables) > runtime PM?=20 If the whole resume process is started by plugging in usb, the interrupt will be triggered still in the resume process so that=20 runtime resume is not yet possible, pm_runtime_get_sync() returns EACCESS > How can we guarantee that the interrupt will be > re-triggered? >=20 The interrupt will not be re-triggered but the handler will be called at some other places... > > + if (!pm_runtime_enabled(twl->dev)) { > > + cancel_delayed_work(&twl->id_workaround_work); > > + schedule_delayed_work(&twl->id_workaround_work, HZ); > > + return IRQ_HANDLED; > > + } > > + ... for example by this delayed work which is already there. Regards, Andreas --Sig_/_BaF6VuUb2T=xBhucJeMtCQ Content-Type: application/pgp-signature Content-Description: OpenPGP digital signature -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEE7sDbhY5mwNpwYgrAfb1qx03ikyQFAluf+OIACgkQfb1qx03i kyRQxRAAp2oiba12dAqVJ0koPsr4bVmUmFxie9a7uIHvqLPGYyWKqcjqhQ26BX/d +SjniI1RzTuybPRP4+lp/cvl96BHVRJmSj4yMku+oE42BC4JcIX1+v3uTif9oNZ7 io2vF/U/q1cVMLL0NCYLBBIL8K3d51SIBAeHdzD2jGWCcbTlly1zyUR/f15NdKlp 5DJDLcfbLFWpl5zZPac3aKz51ZR6fmqCeKqDdY6vrH1TRXOJpGLiZbtCsO0oGzGj 44wfo0g0FMOiaQ676HLlc49VFJzvArmWI0Q3EPdiyYA9fLbLq7mQwHtGF7FPNf3F LjShqq0VKYR4QCzTt7qF2Lw8OiVwz7PtRn8j4etwd4czdQS6MKztFZxsilN2qzi3 GekY8iqQYqYqVPXSA25zhkSirEnWIbY6xwMkRJwQu7axfff3Y851rR3jl3M/Ef+y GEnkCXJIUKenOtZl5T9bqep22FBcq2YO6mHdBIjuK6tW+bYJt5yVmfyBp5lPHMd4 HmwekF2e+XkJhcw8SJ4ELjGQbI+PQ4W4qo8Aqc2wjxXnL55tELpGSlcB53y3JLog MTNcoB6D837mjjd5NO4lZRTZSp8BfQcDh8jM4DEb9/cpnHon0h+zW/4DRyjjeyE5 rdaMm1RkBPhwIAR0vvGtUYlxCot6QNycF+Lx8xIzIYJFEv4gXi4= =l+nW -----END PGP SIGNATURE----- --Sig_/_BaF6VuUb2T=xBhucJeMtCQ--