From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755524AbcHWUq1 (ORCPT ); Tue, 23 Aug 2016 16:46:27 -0400 Received: from smtprelay4.synopsys.com ([198.182.47.9]:37738 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754554AbcHWUqX (ORCPT ); Tue, 23 Aug 2016 16:46:23 -0400 Subject: Re: [RESEND PATCH 3/4] usb: dwc2: assert phy reset when waking up in rk3288 platform To: Randy Li , "linux-usb@vger.kernel.org" References: <4c931176-a09a-546c-d2b6-ea74028c78a2@cogentembedded.com> <1471807905-11323-1-git-send-email-ayaka@soulik.info> From: John Youn CC: "John.Youn@synopsys.com" , "gregkh@linuxfoundation.org" , "robh+dt@kernel.org" , "mark.rutland@arm.com" , "devicetree@vger.kernel.org" , "eddie.cai@rock-chips.com" , "randy.li@rock-chips.com" , "kishon@ti.com" , "linux-kernel@vger.kernel.org" , "heiko@sntech.de" , "linux-rockchip@lists.infradead.org" Message-ID: <49d2baf7-5f81-fc20-a805-f7a378d67a5e@synopsys.com> Date: Tue, 23 Aug 2016 13:46:14 -0700 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.2.0 MIME-Version: 1.0 In-Reply-To: <1471807905-11323-1-git-send-email-ayaka@soulik.info> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.10.186.99] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/21/2016 12:32 PM, Randy Li wrote: > On the rk3288 USB host-only port (the one that's not the OTG-enabled > port) the PHY can get into a bad state when a wakeup is asserted (not > just a wakeup from full system suspend but also a wakeup from > autosuspend). > > We can get the PHY out of its bad state by asserting its "port reset", > but unfortunately that seems to assert a reset onto the USB bus so it > could confuse things if we don't actually deenumerate / reenumerate the > device. > > We can also get the PHY out of its bad state by fully resetting it using > the reset from the CRU (clock reset unit) in chip, which does a more full > reset. The CRU-based reset appears to actually cause devices on the bus > to be removed and reinserted, which fixes the problem (albeit in a hacky > way). > > It's unfortunate that we need to do a full re-enumeration of devices at > wakeup time, but this is better than alternative of letting the bus get > wedged. > > Signed-off-by: Randy Li > --- > drivers/usb/dwc2/core_intr.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/drivers/usb/dwc2/core_intr.c b/drivers/usb/dwc2/core_intr.c > index d85c5c9..f57c48a 100644 > --- a/drivers/usb/dwc2/core_intr.c > +++ b/drivers/usb/dwc2/core_intr.c > @@ -345,6 +345,7 @@ static void dwc2_handle_session_req_intr(struct dwc2_hsotg *hsotg) > static void dwc2_handle_wakeup_detected_intr(struct dwc2_hsotg *hsotg) > { > int ret; > + struct device_node *np = hsotg->dev->of_node; > > /* Clear interrupt */ > dwc2_writel(GINTSTS_WKUPINT, hsotg->regs + GINTSTS); > @@ -379,6 +380,16 @@ static void dwc2_handle_wakeup_detected_intr(struct dwc2_hsotg *hsotg) > /* Restart the Phy Clock */ > pcgcctl &= ~PCGCTL_STOPPCLK; > dwc2_writel(pcgcctl, hsotg->regs + PCGCTL); > + > + /* > + * It is a quirk in Rockchip RK3288, causing by > + * a hardware bug. This will propagate out and > + * eventually we'll re-enumerate the device. > + * Not great but the best we can do Remove the trailing whitespaces in this comment. Run scripts/checkpatch.pl to catch these. > + */ > + if (of_device_is_compatible(np, "rockchip,rk3288-usb")) > + hsotg->phy->ops->reset(hsotg->phy); > + You should probably check for NULL before calling the reset() callback. Also, I'd rather see a generic quirk property that you set for your platform. Something like "phy_reset_on_wakeup_quirk". Also, try to preserve the version tag in your subject for all the patches so that we can easily identify the latest version of the series, like: [PATCH v5 3/4] ... And, typically "RESEND" means there are no code change. Regards, John From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Youn Subject: Re: [RESEND PATCH 3/4] usb: dwc2: assert phy reset when waking up in rk3288 platform Date: Tue, 23 Aug 2016 13:46:14 -0700 Message-ID: <49d2baf7-5f81-fc20-a805-f7a378d67a5e@synopsys.com> References: <4c931176-a09a-546c-d2b6-ea74028c78a2@cogentembedded.com> <1471807905-11323-1-git-send-email-ayaka@soulik.info> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1471807905-11323-1-git-send-email-ayaka-xPW3/0Ywev/iB9QmIjCX8w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-rockchip" Errors-To: linux-rockchip-bounces+glpar-linux-rockchip=m.gmane.org-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org To: Randy Li , "linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" Cc: "mark.rutland-5wv7dgnIgG8@public.gmane.org" , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "heiko-4mtYJXux2i+zQB+pC5nmwQ@public.gmane.org" , "gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org" , "randy.li-TNX95d0MmH7DzftRWevZcw@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "John.Youn-HKixBCOQz3hWk0Htik3J/w@public.gmane.org" , "linux-rockchip-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , "robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org" , "eddie.cai-TNX95d0MmH7DzftRWevZcw@public.gmane.org" , "kishon-l0cyMroinI0@public.gmane.org" List-Id: devicetree@vger.kernel.org On 8/21/2016 12:32 PM, Randy Li wrote: > On the rk3288 USB host-only port (the one that's not the OTG-enabled > port) the PHY can get into a bad state when a wakeup is asserted (not > just a wakeup from full system suspend but also a wakeup from > autosuspend). > > We can get the PHY out of its bad state by asserting its "port reset", > but unfortunately that seems to assert a reset onto the USB bus so it > could confuse things if we don't actually deenumerate / reenumerate the > device. > > We can also get the PHY out of its bad state by fully resetting it using > the reset from the CRU (clock reset unit) in chip, which does a more full > reset. The CRU-based reset appears to actually cause devices on the bus > to be removed and reinserted, which fixes the problem (albeit in a hacky > way). > > It's unfortunate that we need to do a full re-enumeration of devices at > wakeup time, but this is better than alternative of letting the bus get > wedged. > > Signed-off-by: Randy Li > --- > drivers/usb/dwc2/core_intr.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/drivers/usb/dwc2/core_intr.c b/drivers/usb/dwc2/core_intr.c > index d85c5c9..f57c48a 100644 > --- a/drivers/usb/dwc2/core_intr.c > +++ b/drivers/usb/dwc2/core_intr.c > @@ -345,6 +345,7 @@ static void dwc2_handle_session_req_intr(struct dwc2_hsotg *hsotg) > static void dwc2_handle_wakeup_detected_intr(struct dwc2_hsotg *hsotg) > { > int ret; > + struct device_node *np = hsotg->dev->of_node; > > /* Clear interrupt */ > dwc2_writel(GINTSTS_WKUPINT, hsotg->regs + GINTSTS); > @@ -379,6 +380,16 @@ static void dwc2_handle_wakeup_detected_intr(struct dwc2_hsotg *hsotg) > /* Restart the Phy Clock */ > pcgcctl &= ~PCGCTL_STOPPCLK; > dwc2_writel(pcgcctl, hsotg->regs + PCGCTL); > + > + /* > + * It is a quirk in Rockchip RK3288, causing by > + * a hardware bug. This will propagate out and > + * eventually we'll re-enumerate the device. > + * Not great but the best we can do Remove the trailing whitespaces in this comment. Run scripts/checkpatch.pl to catch these. > + */ > + if (of_device_is_compatible(np, "rockchip,rk3288-usb")) > + hsotg->phy->ops->reset(hsotg->phy); > + You should probably check for NULL before calling the reset() callback. Also, I'd rather see a generic quirk property that you set for your platform. Something like "phy_reset_on_wakeup_quirk". Also, try to preserve the version tag in your subject for all the patches so that we can easily identify the latest version of the series, like: [PATCH v5 3/4] ... And, typically "RESEND" means there are no code change. Regards, John