From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750954AbcEIAY2 (ORCPT ); Sun, 8 May 2016 20:24:28 -0400 Received: from e23smtp08.au.ibm.com ([202.81.31.141]:47326 "EHLO e23smtp08.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750872AbcEIAY0 (ORCPT ); Sun, 8 May 2016 20:24:26 -0400 X-IBM-Helo: d23dlp02.au.ibm.com X-IBM-MailFrom: benh@au1.ibm.com X-IBM-RcptTo: linux-kernel@vger.kernel.org;linux-usb@vger.kernel.org Message-ID: <1462753402.20290.95.camel@au1.ibm.com> Subject: Re: usb: dwc2: regression on MyBook Live Duo / Canyonlands since 4.3.0-rc4 From: Benjamin Herrenschmidt Reply-To: benh@au1.ibm.com To: Christian Lamparter Cc: linux-usb@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, a.seppala@gmail.com, johnyoun@synopsys.com, gregkh@linuxfoundation.org Date: Mon, 09 May 2016 10:23:22 +1000 In-Reply-To: <1908894.Nkk1LXQkFm@debian64> References: <4231696.iL6nGs74X8@debian64> <1462704055.20290.93.camel@au1.ibm.com> <1908894.Nkk1LXQkFm@debian64> Organization: IBM Australia Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.18.5.2 (3.18.5.2-1.fc23) Mime-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16050900-0029-0000-0000-0000459C3B71 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 2016-05-08 at 13:44 +0200, Christian Lamparter wrote: > On Sunday, May 08, 2016 08:40:55 PM Benjamin Herrenschmidt wrote: > > > > On Sun, 2016-05-08 at 00:54 +0200, Christian Lamparter via Linuxppc-dev  > > wrote: > > > > > > I've been looking in getting the MyBook Live Duo's USB OTG port > > > to function. The SoC is a APM82181. Which has a PowerPC 464 core > > > and related to the supported canyonlands architecture in > > > arch/powerpc/. > > > > > > Currently in -next the dwc2 module doesn't load:  > > Smells like the APM implementation is little endian. You might need to > > use a flag to indicate what endian to use instead and set it > > appropriately based on some DT properties. > I tried. As per common-properties[0], I added little-endian; but it has no > effect. I looked in dwc2_driver_probe and found no way of specifying the > endian of the device. It all comes down to the dwc2_readl & dwc2_writel > accessors. These - sadly - have been hardwired to use __raw_readl and > __raw_writel. So, it's always "native-endian". While common-properties > says little-endian should be preferred. Right, I meant, you should produce a patch adding a runtime test inside those functions based on a device-tree property, a bit like we do for some of the HCDs like OHCI, EHCI etc... Cheers, Ben. > > > > > > > > dwc2 4bff80000.usbotg: dwc2_core_reset() HANG! AHB Idle GRSTCTL=80 > > > dwc2 4bff80000.usbotg: Bad value for GSNPSID: 0x0a29544f > > > > > > Looking at the Bad GSNPSID value: 0x0a29544f. It is obvious that > > > this is an endian problem. git finds this patch: > > > > > > commit 95c8bc3609440af5e4a4f760b8680caea7424396 > > > Author: Antti Seppälä > > > Date:   Thu Aug 20 21:41:07 2015 +0300 > > > > > >     usb: dwc2: Use platform endianness when accessing registers > > > > > >     This patch is necessary to access dwc2 registers correctly on > > > big-endian > > >     systems such as the mips based SoCs made by Lantiq. Then dwc2 can > > > be > > >     used to replace ifx-hcd driver for Lantiq platforms found e.g. in > > >     OpenWrt. > > >      > > >     The patch was autogenerated with the following commands: > > >     $EDITOR core.h > > >     sed -i "s/\/dwc2_readl/g" *.c hcd.h hw.h > > >     sed -i "s/\/dwc2_writel/g" *.c hcd.h hw.h > > >      > > >     Some files were then hand-edited to fix checkpatch.pl warnings > > > about > > >     too long lines. > > > > > > which unfortunately, broke the USB-OTG port on the MyBook Live Duo. > > > Reverting to the readl / writel: > > > > > > ---  > > > diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h > > > index 3c58d63..c021c1f 100644 > > > --- a/drivers/usb/dwc2/core.h > > > +++ b/drivers/usb/dwc2/core.h > > > @@ -66,7 +66,7 @@ > > >   > > >  static inline u32 dwc2_readl(const void __iomem *addr) > > >  { > > > - u32 value = __raw_readl(addr); > > > + u32 value = readl(addr); > > >   > > >   /* In order to preserve endianness __raw_* operation is > > > used. Therefore > > >    * a barrier is needed to ensure IO access is not re-ordered  > > > across > > > @@ -78,7 +78,7 @@ static inline u32 dwc2_readl(const void __iomem > > > *addr) > > >   > > >  static inline void dwc2_writel(u32 value, void __iomem *addr) > > >  { > > > - __raw_writel(value, addr); > > > + writel(value, addr); > > >   > > >   /* > > >    * In order to preserve endianness __raw_* operation is > > > used. Therefore > > > > > > --- > > > > > > restores the dwc-otg port to full working order: > > > dwc2 4bff80000.usbotg: Specified GNPTXFDEP=1024 > 256 > > > dwc2 4bff80000.usbotg: EPs: 3, shared fifos, 2042 entries in SPRAM > > > dwc2 4bff80000.usbotg: DWC OTG Controller > > > dwc2 4bff80000.usbotg: new USB bus registered, assigned bus number 1 > > > dwc2 4bff80000.usbotg: irq 33, io mem 0x00000000 > > > hub 1-0:1.0: USB hub found > > > hub 1-0:1.0: 1 port detected > > > root@mbl:~# usb 1-1: new high-speed USB device number 2 using dwc2 > > > > > > So, what to do? >      ^^^ > > Regards, > Christian > > [0] > > -- > To unsubscribe from this list: send the line "unsubscribe linux-usb" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at  http://vger.kernel.org/majordomo-info.html