From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755198AbcHYSX4 (ORCPT ); Thu, 25 Aug 2016 14:23:56 -0400 Received: from smtprelay.synopsys.com ([198.182.60.111]:38109 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751672AbcHYSXx (ORCPT ); Thu, 25 Aug 2016 14:23:53 -0400 Subject: Re: [RESEND PATCH 3/4] usb: dwc2: assert phy reset when waking up in rk3288 platform To: Randy Li , John Youn , Randy Li , "linux-usb@vger.kernel.org" , Felipe Balbi References: <4c931176-a09a-546c-d2b6-ea74028c78a2@cogentembedded.com> <1471807905-11323-1-git-send-email-ayaka@soulik.info> <49d2baf7-5f81-fc20-a805-f7a378d67a5e@synopsys.com> <76f0ffdb-a3c6-f1e6-8177-b254ff5badaa@rock-chips.com> From: John Youn CC: "mark.rutland@arm.com" , "devicetree@vger.kernel.org" , "heiko@sntech.de" , "gregkh@linuxfoundation.org" , "linux-kernel@vger.kernel.org" , "linux-rockchip@lists.infradead.org" , "robh+dt@kernel.org" , "eddie.cai@rock-chips.com" , "kishon@ti.com" Message-ID: Date: Thu, 25 Aug 2016 11:23:45 -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: <76f0ffdb-a3c6-f1e6-8177-b254ff5badaa@rock-chips.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.9.139.124] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/24/2016 1:54 AM, Randy Li wrote: > > > On 08/24/2016 04:46 AM, John Youn wrote: >> 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. > I see. >> >>> + */ >>> + 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. > Sure. >> >> Also, I'd rather see a generic quirk property that you set for your >> platform. >> >> Something like "phy_reset_on_wakeup_quirk". > But Rob Herring want me to implied by the SoC specific compatible > string. I agree with him. It is certainly bug in RK3288 platform. > It is no found no the other platform. Ok, I missed that before. Based on the drivers I'm familiar with (like dwc3), you would typically add a "quirk" anyways. Felipe, Do you have some policy or preference on this? 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: Thu, 25 Aug 2016 11:23:45 -0700 Message-ID: References: <4c931176-a09a-546c-d2b6-ea74028c78a2@cogentembedded.com> <1471807905-11323-1-git-send-email-ayaka@soulik.info> <49d2baf7-5f81-fc20-a805-f7a378d67a5e@synopsys.com> <76f0ffdb-a3c6-f1e6-8177-b254ff5badaa@rock-chips.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <76f0ffdb-a3c6-f1e6-8177-b254ff5badaa-TNX95d0MmH7DzftRWevZcw@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 , John Youn , Randy Li , "linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Felipe Balbi 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" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "kishon-l0cyMroinI0@public.gmane.org" , "linux-rockchip-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , "robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org" , "eddie.cai-TNX95d0MmH7DzftRWevZcw@public.gmane.org" List-Id: devicetree@vger.kernel.org On 8/24/2016 1:54 AM, Randy Li wrote: > > > On 08/24/2016 04:46 AM, John Youn wrote: >> 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. > I see. >> >>> + */ >>> + 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. > Sure. >> >> Also, I'd rather see a generic quirk property that you set for your >> platform. >> >> Something like "phy_reset_on_wakeup_quirk". > But Rob Herring want me to implied by the SoC specific compatible > string. I agree with him. It is certainly bug in RK3288 platform. > It is no found no the other platform. Ok, I missed that before. Based on the drivers I'm familiar with (like dwc3), you would typically add a "quirk" anyways. Felipe, Do you have some policy or preference on this? Regards, John