Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753797AbbGFIUW (ORCPT ); Mon, 6 Jul 2015 04:20:22 -0400 Received: from galahad.ideasonboard.com ([185.26.127.97]:56432 "EHLO galahad.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753653AbbGFIUS (ORCPT ); Mon, 6 Jul 2015 04:20:18 -0400 From: Laurent Pinchart To: Phil Edworthy Cc: Yoshihiro Shimoda , Kuninori Morimoto , Greg Kroah-Hartman , Felipe Balbi , Ulrich Hecht , Kishon Vijay Abraham I , Sergei Shtylyov , linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, linux-sh@vger.kernel.org Subject: Re: [PATCH v3] usb: renesas_usbhs: Allow an OTG PHY driver to provide VBUS Date: Mon, 06 Jul 2015 11:20:25 +0300 Message-ID: <3446210.Evs1k3c1oP@avalon> User-Agent: KMail/4.14.8 (Linux/4.0.5-gentoo; KDE/4.14.8; x86_64; ; ) In-Reply-To: <1435832793-9999-1-git-send-email-phil.edworthy@renesas.com> References: <2896957.Pcl0CbmdvL@avalon> <1435832793-9999-1-git-send-email-phil.edworthy@renesas.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6439 Lines: 194 Hi Phil, Thank you for the patch. On Thursday 02 July 2015 11:26:33 Phil Edworthy wrote: > These changes allow a PHY driver to trigger a VBUS interrupt and > to provide the value of VBUS. > > Signed-off-by: Phil Edworthy > > --- > v3: > - Changed how indirect vbus is plumbed in. > - Removed unnecessary (void) on call to otg_set_peripheral. > - Moved code that connects to bus through transceiver so it > is before setting gpriv->driver. > > v2: > - vbus variables changed from int to bool. > - dev_info() changed to dev_err() > --- > drivers/usb/renesas_usbhs/common.c | 8 +++++-- > drivers/usb/renesas_usbhs/common.h | 2 ++ > drivers/usb/renesas_usbhs/mod_gadget.c | 38 +++++++++++++++++++++++++++++++ > 3 files changed, 46 insertions(+), 2 deletions(-) > > diff --git a/drivers/usb/renesas_usbhs/common.c > b/drivers/usb/renesas_usbhs/common.c index 0f7e850..15e67d8 100644 > --- a/drivers/usb/renesas_usbhs/common.c > +++ b/drivers/usb/renesas_usbhs/common.c > @@ -379,7 +379,10 @@ static void usbhsc_hotplug(struct usbhs_priv *priv) > /* > * get vbus status from platform > */ > - enable = usbhs_platform_call(priv, get_vbus, pdev); > + if (priv->vbus_is_indirect) > + enable = priv->vbus_indirect_value; > + else > + enable = usbhs_platform_call(priv, get_vbus, pdev); > > /* > * get id from platform > @@ -662,7 +665,8 @@ static int usbhs_probe(struct platform_device *pdev) > pm_runtime_enable(&pdev->dev); > if (!usbhsc_flags_has(priv, USBHSF_RUNTIME_PWCTRL)) { > usbhsc_power_ctrl(priv, 1); > - usbhs_mod_autonomy_mode(priv); > + if (!priv->vbus_is_indirect) Isn't this racy ? The vbus_session operation is called by transceivers from interrupt handlers or work queues. Do we have a guarantee that it will be called at least once before this code is reached ? Please see below for a possible way to fix this. > + usbhs_mod_autonomy_mode(priv); > } > > /* > diff --git a/drivers/usb/renesas_usbhs/common.h > b/drivers/usb/renesas_usbhs/common.h index 8c5fc12..478700c 100644 > --- a/drivers/usb/renesas_usbhs/common.h > +++ b/drivers/usb/renesas_usbhs/common.h > @@ -255,6 +255,8 @@ struct usbhs_priv { > struct renesas_usbhs_driver_param dparam; > > struct delayed_work notify_hotplug_work; > + bool vbus_is_indirect; > + bool vbus_indirect_value; > struct platform_device *pdev; > > struct extcon_dev *edev; > diff --git a/drivers/usb/renesas_usbhs/mod_gadget.c > b/drivers/usb/renesas_usbhs/mod_gadget.c index dc2aa32..93ad4ea 100644 > --- a/drivers/usb/renesas_usbhs/mod_gadget.c > +++ b/drivers/usb/renesas_usbhs/mod_gadget.c > @@ -21,6 +21,7 @@ > #include > #include > #include > +#include > #include "common.h" > > /* > @@ -50,6 +51,7 @@ struct usbhsg_gpriv { > int uep_size; > > struct usb_gadget_driver *driver; > + struct usb_phy *transceiver; > > u32 status; > #define USBHSG_STATUS_STARTED (1 << 0) > @@ -882,12 +884,25 @@ static int usbhsg_gadget_start(struct usb_gadget > *gadget, { > struct usbhsg_gpriv *gpriv = usbhsg_gadget_to_gpriv(gadget); > struct usbhs_priv *priv = usbhsg_gpriv_to_priv(gpriv); > + struct device *dev = usbhs_priv_to_dev(priv); > + int ret; > > if (!driver || > !driver->setup || > driver->max_speed < USB_SPEED_FULL) > return -EINVAL; > > + /* connect to bus through transceiver */ > + if (!IS_ERR_OR_NULL(gpriv->transceiver)) { > + ret = otg_set_peripheral(gpriv->transceiver->otg, > + &gpriv->gadget); > + if (ret) { > + dev_err(dev, "%s: can't bind to transceiver\n", > + gpriv->gadget.name); > + return ret; > + } > + } > + How is this change related to the topic ? I'm not too familiar with this driver so I might just have missed something, but then others could as well, and the commit message could do with a bit more information. > /* first hook up the driver ... */ > gpriv->driver = driver; > > @@ -900,6 +915,10 @@ static int usbhsg_gadget_stop(struct usb_gadget > *gadget) struct usbhs_priv *priv = usbhsg_gpriv_to_priv(gpriv); > > usbhsg_try_stop(priv, USBHSG_STATUS_REGISTERD); > + > + if (!IS_ERR_OR_NULL(gpriv->transceiver)) > + otg_set_peripheral(gpriv->transceiver->otg, NULL); > + > gpriv->driver = NULL; > > return 0; > @@ -947,12 +966,27 @@ static int usbhsg_set_selfpowered(struct usb_gadget > *gadget, int is_self) return 0; > } > > +static int usbhsg_vbus_session(struct usb_gadget *gadget, int is_active) > +{ > + struct usbhsg_gpriv *gpriv = usbhsg_gadget_to_gpriv(gadget); > + struct usbhs_priv *priv = usbhsg_gpriv_to_priv(gpriv); > + struct platform_device *pdev = usbhs_priv_to_pdev(priv); > + > + priv->vbus_is_indirect = 1; vbus_is_indirect is never reset to 0. Shouldn't you set it to 1 (or rather to true) in usbhs_mod_gadget_probe() if an external transceiver is found ? What would you think of implementing and wiring up the get_vbus operation in usbhs_mod_gadget_probe() in the same way that usbhs_mod_autonomy_mode() does, and return the value of vbus_indirect_value there ? You could then get rid of the vbus_is_indirect field and move the vbus_indirect_value field to struct usbhsg_gpriv, removing the need to modify drivers/usb/renesas_usbhs/common.c. It should also solve the race condition mentioned above. > + priv->vbus_indirect_value = !!is_active; > + > + renesas_usbhs_call_notify_hotplug(pdev); > + > + return 0; > +} > + > static const struct usb_gadget_ops usbhsg_gadget_ops = { > .get_frame = usbhsg_get_frame, > .set_selfpowered = usbhsg_set_selfpowered, > .udc_start = usbhsg_gadget_start, > .udc_stop = usbhsg_gadget_stop, > .pullup = usbhsg_pullup, > + .vbus_session = usbhsg_vbus_session, > }; > > static int usbhsg_start(struct usbhs_priv *priv) > @@ -994,6 +1028,10 @@ int usbhs_mod_gadget_probe(struct usbhs_priv *priv) > goto usbhs_mod_gadget_probe_err_gpriv; > } > > + gpriv->transceiver = usb_get_phy(USB_PHY_TYPE_UNDEFINED); > + dev_info(dev, "%s transceiver found\n", > + gpriv->transceiver ? "" : "No"); > + > /* > * CAUTION > * -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/