Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751852AbbHSAUE (ORCPT ); Tue, 18 Aug 2015 20:20:04 -0400 Received: from us01smtprelay-2.synopsys.com ([198.182.60.111]:39375 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750777AbbHSAT6 convert rfc822-to-8bit (ORCPT ); Tue, 18 Aug 2015 20:19:58 -0400 From: John Youn To: Yunzhi Li , "jwerner@chromium.org" , "dianders@chromium.org" CC: "huangtao@rock-chips.com" , "cf@rock-chips.com" , "hl@rock-chips.com" , John Youn , Greg Kroah-Hartman , "linux-usb@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v2] usb: dwc2: reset dwc2 core before dwc2_get_hwparams() Thread-Topic: [PATCH v2] usb: dwc2: reset dwc2 core before dwc2_get_hwparams() Thread-Index: AQHQ2ZoF5pUJovT8502n5tIeDBFXnw== Date: Wed, 19 Aug 2015 00:19:55 +0000 Message-ID: <2B3535C5ECE8B5419E3ECBE30077290901DC335B43@us01wembx1.internal.synopsys.com> References: <1439890818-22138-1-git-send-email-lyz@rock-chips.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.12.65.47] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3180 Lines: 86 On 8/18/2015 2:41 AM, Yunzhi Li wrote: > We initiate dwc2 usb controller in BIOS, dwc2_core_reset() should > be called before dwc2_get_hwparams() to reset core registers to > default value. Without this the FIFO setting might be incorrect > because calculating FIFO size need power-on value of > GRXFSIZ/GNPTXFSIZ/HPTXFSIZ registers. > > This patch could avoid warnning massage like in rk3288 platform: > [ 2.074764] dwc2 ff580000.usb: 256 invalid for > host_perio_tx_fifo_size. Check HW configuration. > > Signed-off-by: Yunzhi Li > > --- > > drivers/usb/dwc2/core.c | 2 +- > drivers/usb/dwc2/core.h | 1 + > drivers/usb/dwc2/platform.c | 6 ++++++ > 3 files changed, 8 insertions(+), 1 deletion(-) > > diff --git a/drivers/usb/dwc2/core.c b/drivers/usb/dwc2/core.c > index c3cc1a7..86d1d65 100644 > --- a/drivers/usb/dwc2/core.c > +++ b/drivers/usb/dwc2/core.c > @@ -474,7 +474,7 @@ static void dwc2_init_fs_ls_pclk_sel(struct dwc2_hsotg *hsotg) > * Do core a soft reset of the core. Be careful with this because it > * resets all the internal state machines of the core. > */ > -static int dwc2_core_reset(struct dwc2_hsotg *hsotg) > +int dwc2_core_reset(struct dwc2_hsotg *hsotg) > { > u32 greset; > int count = 0; > diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h > index 0ed87620..5d95aec 100644 > --- a/drivers/usb/dwc2/core.h > +++ b/drivers/usb/dwc2/core.h > @@ -846,6 +846,7 @@ enum dwc2_halt_status { > * The following functions support initialization of the core driver component > * and the DWC_otg controller > */ > +extern int dwc2_core_reset(struct dwc2_hsotg *hsotg); > extern void dwc2_core_host_init(struct dwc2_hsotg *hsotg); > extern int dwc2_enter_hibernation(struct dwc2_hsotg *hsotg); > extern int dwc2_exit_hibernation(struct dwc2_hsotg *hsotg, bool restore); > diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c > index 9093530..8d3be4a 100644 > --- a/drivers/usb/dwc2/platform.c > +++ b/drivers/usb/dwc2/platform.c > @@ -243,6 +243,12 @@ static int dwc2_driver_probe(struct platform_device *dev) > spin_lock_init(&hsotg->lock); > mutex_init(&hsotg->init_mutex); > > + /* > + * Reset before dwc2_get_hwparams() then it could get power-on real > + * reset value form registers. > + */ > + dwc2_core_reset(hsotg); > + > /* Detect config values from hardware */ > retval = dwc2_get_hwparams(hsotg); > if (retval) > Hi Yunzhi, My concern is with the delays due to calling the dwc2_core_reset during probe. You could factor out the assertion of the core soft reset from the dwc2_core_reset and just use that before calling dwc2_get_hwparams(). You had previously addressed the lengthy probe time issue here: http://marc.info/?l=linux-usb&m=142357721304377 This reducing delays patch looks reasonable to me and I think it should get merged also. I'll do some testing with it later this week. John -- 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/