From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934335AbeCEKdK (ORCPT ); Mon, 5 Mar 2018 05:33:10 -0500 Received: from mail.bootlin.com ([62.4.15.54]:52406 "EHLO mail.bootlin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933519AbeCEKdH (ORCPT ); Mon, 5 Mar 2018 05:33:07 -0500 Date: Mon, 5 Mar 2018 11:32:54 +0100 From: Antoine Tenart To: Alexander Monakov Cc: linux-kernel@vger.kernel.org, Kishon Vijay Abraham I , Antoine Tenart , Jisheng.Zhang@synaptics.com Subject: Re: [PATCH] phy: berlin-usb: adjust USB_PHY_RX_CTRL init flags Message-ID: <20180305103254.GH1156@kwain> References: <20180304181807.20825-1-amonakov@ispras.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20180304181807.20825-1-amonakov@ispras.ru> User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Alexander, I've added Jisheng in Cc so he can have a look at this. Thanks! Antoine On Sun, Mar 04, 2018 at 09:18:07PM +0300, Alexander Monakov wrote: > Make the value written into the USB_PHY_RX_CTRL configuration register > match 0xAA79 value written by manufacturer-supplied kernels for Sony > NSZ-GS7 (Berlin2 SoC), Google Chromecast and Valve Steam Link (BG2CD). > > This fixes timeouts communicating to the internal hub on Steam Link. > > Cc: Kishon Vijay Abraham I > Cc: Antoine Tenart > Signed-off-by: Alexander Monakov > --- > Hello, > > I'm trying to run mainline kernel on "Steam Link" device built around > Marvell BG2CD SoC, and in doing so I've found that USB almost always > fails to initialize with timeout errors when connecting to the hub: > > [ 0.223563] usb usb1: New USB device found, idVendor=1d6b, idProduct=0002 > [ 0.223580] usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1 > [ 0.223596] usb usb1: Product: EHCI Host Controller > [ 0.223608] usb usb1: Manufacturer: Linux 4.15.0-00014-gc6f881cd62dc-dirty ehci_hcd > [ 0.223624] usb usb1: SerialNumber: ci_hdrc.0 > [ 0.223985] hub 1-0:1.0: USB hub found > [ 0.224022] hub 1-0:1.0: 1 port detected > [ 0.524726] ci_hdrc ci_hdrc.0: port 1 reset error -110 > [ 1.044673] ci_hdrc ci_hdrc.0: port 1 reset error -110 > [ 1.399721] mwifiex_sdio mmc0:0001:1: info: FW download over, size 814048 bytes > [ 1.484666] ci_hdrc ci_hdrc.0: port 1 reset error -110 > [ 2.113451] mwifiex_sdio mmc0:0001:1: WLAN FW is active > [ 2.113725] sdio platform data not available > [ 2.192570] mwifiex_sdio mmc0:0001:1: info: MWIFIEX VERSION: mwifiex 1.0 (15.68.7.p112) > [ 2.192599] mwifiex_sdio mmc0:0001:1: driver_version = mwifiex 1.0 (15.68.7.p112) > [ 2.213433] usb 1-1: new high-speed USB device number 2 using ci_hdrc > [ 2.294676] ci_hdrc ci_hdrc.0: port 1 reset error -110 > > and so on until... > > [ 19.254658] ci_hdrc ci_hdrc.0: port 1 reset error -110 > [ 19.913433] usb usb1-port1: Cannot enable. Maybe the USB cable is bad? > [ 19.913472] usb usb1-port1: unable to enumerate USB device > > I've inspected how the original kernel performs phy initialization, and > found that the value written into the USB_PHY_RX_CTRL register differs > in one field. Correcting the field is enough to stabilize it in my case. > > I don't know where the _260 choice in mainline source comes from. I've > checked three publicly available kernels for devices with this phy, and > they all write the same value, 0xAA79. > > FWIW, this is not the only difference I've found. Other kernels also: > - do not touch TX config registers; > - drive a particular GPIO low before and high after configuring the phy. > > I am unsure if anything needs to or can be done about those differences. > > Thanks. > Alexander > > drivers/phy/marvell/phy-berlin-usb.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/phy/marvell/phy-berlin-usb.c b/drivers/phy/marvell/phy-berlin-usb.c > index 2017751ede26..8f2b5cae360f 100644 > --- a/drivers/phy/marvell/phy-berlin-usb.c > +++ b/drivers/phy/marvell/phy-berlin-usb.c > @@ -127,7 +127,7 @@ static int phy_berlin_usb_power_on(struct phy *phy) > writel(V2I_VCO_RATIO(0x5) | R_ROTATE_0 | ANA_TEST_DC_CTRL(0x5), > priv->base + USB_PHY_ANALOG); > writel(PHASE_FREEZE_DLY_4_CL | ACK_LENGTH_16_CL | SQ_LENGTH_12 | > - DISCON_THRESHOLD_260 | SQ_THRESHOLD(0xa) | LPF_COEF(0x2) | > + DISCON_THRESHOLD_270 | SQ_THRESHOLD(0xa) | LPF_COEF(0x2) | > INTPL_CUR_30, priv->base + USB_PHY_RX_CTRL); > > writel(TX_VDD12_13 | TX_OUT_AMP(0x3), priv->base + USB_PHY_TX_CTRL1); > -- > 2.11.0 > -- Antoine Ténart, Bootlin (formerly Free Electrons) Embedded Linux and Kernel engineering https://bootlin.com