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From: Jun Li <jun.li@nxp.com>
To: Thinh Nguyen <Thinh.Nguyen@synopsys.com>,
	Felipe Balbi <balbi@kernel.org>, Jun Li <lijun.kernel@gmail.com>
Cc: John Stultz <john.stultz@linaro.org>,
	lkml <linux-kernel@vger.kernel.org>,
	Yu Chen <chenyu56@huawei.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Rob Herring <robh+dt@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	ShuFan Lee <shufan_lee@richtek.com>,
	Heikki Krogerus <heikki.krogerus@linux.intel.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Chunfeng Yun <chunfeng.yun@mediatek.com>,
	Hans de Goede <hdegoede@redhat.com>,
	Andy Shevchenko <andy.shevchenko@gmail.com>,
	Valentin Schneider <valentin.schneider@arm.com>,
	Jack Pham <jackp@codeaurora.org>,
	Linux USB List <linux-usb@vger.kernel.org>,
	"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
	<devicetree@vger.kernel.org>, Peter Chen <peter.chen@nxp.com>
Subject: RE: [PATCH v4 3/9] usb: dwc3: Increase timeout for CmdAct cleared by device controller
Date: Thu, 21 May 2020 07:33:25 +0000	[thread overview]
Message-ID: <VE1PR04MB652863A8406D25EEF2CE483389B70@VE1PR04MB6528.eurprd04.prod.outlook.com> (raw)
In-Reply-To: <1c16bdb6-8d8d-1e1b-f08b-b3963f905eb0@synopsys.com>

Hi Thinh,
> -----Original Message-----
> From: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
> Sent: 2020年5月21日 9:56
> To: Jun Li <jun.li@nxp.com>; Felipe Balbi <balbi@kernel.org>; Jun Li
> <lijun.kernel@gmail.com>
> Cc: John Stultz <john.stultz@linaro.org>; lkml <linux-kernel@vger.kernel.org>; Yu
> Chen <chenyu56@huawei.com>; Greg Kroah-Hartman <gregkh@linuxfoundation.org>; Rob
> Herring <robh+dt@kernel.org>; Mark Rutland <mark.rutland@arm.com>; ShuFan Lee
> <shufan_lee@richtek.com>; Heikki Krogerus <heikki.krogerus@linux.intel.com>;
> Suzuki K Poulose <suzuki.poulose@arm.com>; Chunfeng Yun
> <chunfeng.yun@mediatek.com>; Hans de Goede <hdegoede@redhat.com>; Andy Shevchenko
> <andy.shevchenko@gmail.com>; Valentin Schneider <valentin.schneider@arm.com>;
> Jack Pham <jackp@codeaurora.org>; Linux USB List <linux-usb@vger.kernel.org>; open
> list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS <devicetree@vger.kernel.org>;
> Peter Chen <peter.chen@nxp.com>
> Subject: Re: [PATCH v4 3/9] usb: dwc3: Increase timeout for CmdAct cleared by device
> controller
> 
> Thinh Nguyen wrote:
> > Jun Li wrote:
> >> Hi
> >>
> >>> -----Original Message-----
> >>> From: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
> >>> Sent: 2020年5月19日 14:46
> >>> To: Jun Li <jun.li@nxp.com>; Felipe Balbi <balbi@kernel.org>; Jun Li
> >>> <lijun.kernel@gmail.com>
> >>> Cc: John Stultz <john.stultz@linaro.org>; lkml
> >>> <linux-kernel@vger.kernel.org>; Yu Chen <chenyu56@huawei.com>; Greg
> >>> Kroah-Hartman <gregkh@linuxfoundation.org>; Rob Herring
> >>> <robh+dt@kernel.org>; Mark Rutland <mark.rutland@arm.com>; ShuFan
> >>> Lee <shufan_lee@richtek.com>; Heikki Krogerus
> >>> <heikki.krogerus@linux.intel.com>;
> >>> Suzuki K Poulose <suzuki.poulose@arm.com>; Chunfeng Yun
> >>> <chunfeng.yun@mediatek.com>; Hans de Goede <hdegoede@redhat.com>;
> >>> Andy Shevchenko <andy.shevchenko@gmail.com>; Valentin Schneider
> >>> <valentin.schneider@arm.com>; Jack Pham <jackp@codeaurora.org>;
> >>> Linux USB List <linux-usb@vger.kernel.org>; open list:OPEN FIRMWARE
> >>> AND FLATTENED DEVICE TREE BINDINGS <devicetree@vger.kernel.org>;
> >>> Peter Chen <peter.chen@nxp.com>
> >>> Subject: Re: [PATCH v4 3/9] usb: dwc3: Increase timeout for CmdAct
> >>> cleared by device controller
> >>>
> >>> Thinh Nguyen wrote:
> >>>> Jun Li wrote:
> >>>>>> -----Original Message-----
> >>>>>> From: Felipe Balbi <balbif@gmail.com> On Behalf Of Felipe Balbi
> >>>>>> Sent: 2020年5月16日 19:57
> >>>>>> To: Jun Li <jun.li@nxp.com>; Thinh Nguyen
> >>>>>> <Thinh.Nguyen@synopsys.com>; Jun Li <lijun.kernel@gmail.com>
> >>>>>> Cc: John Stultz <john.stultz@linaro.org>; lkml
> >>>>>> <linux-kernel@vger.kernel.org>; Yu Chen <chenyu56@huawei.com>;
> >>>>>> Greg Kroah-Hartman <gregkh@linuxfoundation.org>; Rob Herring
> >>>>>> <robh+dt@kernel.org>; Mark Rutland <mark.rutland@arm.com>; ShuFan
> >>>>>> Lee <shufan_lee@richtek.com>; Heikki Krogerus
> >>>>>> <heikki.krogerus@linux.intel.com>;
> >>>>>> Suzuki K Poulose <suzuki.poulose@arm.com>; Chunfeng Yun
> >>>>>> <chunfeng.yun@mediatek.com>; Hans de Goede <hdegoede@redhat.com>;
> >>>>>> Andy Shevchenko <andy.shevchenko@gmail.com>; Valentin Schneider
> >>>>>> <valentin.schneider@arm.com>; Jack Pham <jackp@codeaurora.org>;
> >>>>>> Linux USB List <linux-usb@vger.kernel.org>; open list:OPEN
> >>>>>> FIRMWARE AND FLATTENED DEVICE TREE BINDINGS
> >>>>>> <devicetree@vger.kernel.org>; Peter Chen <peter.chen@nxp.com>;
> >>>>>> Thinh Nguyen <Thinh.Nguyen@synopsys.com>
> >>>>>> Subject: RE: [PATCH v4 3/9] usb: dwc3: Increase timeout for
> >>>>>> CmdAct cleared by device controller
> >>>>>>
> >>>>>>
> >>>>>> Hi,
> >>>>>>
> >>>>>> Jun Li <jun.li@nxp.com> writes:
> >>>>>>>>>> Hi Thinh, could you comment this?
> >>>>>>>>> You only need to wake up the usb2 phy when issuing the command
> >>>>>>>>> while running in highspeed or below. If you're running in SS
> >>>>>>>>> or higher, internally the controller does it for you for usb3 phy.
> >>>>>>>>> In Jun's case, it seems like it takes longer for his phy to wake up.
> >>>>>>>>>
> >>>>>>>>> IMO, in this case, I think it's fine to increase the command timeout.
> >>>>>>>> Is there an upper limit to this? Is 32k clock the slowest that
> >>>>>>>> can be fed to the PHY as a suspend clock?
> >>>>>>> Yes, 32K clock is the slowest, Per DWC3 document on Power Down
> >>>>>>> Scale (bits 31:19 of GCTL):
> >>>>>>>
> >>>>>>> "Power Down Scale (PwrDnScale)
> >>>>>>> The USB3 suspend_clk input replaces pipe3_rx_pclk as a clock
> >>>>>>> source to a small part of the USB3 controller that operates when
> >>>>>>> the SS PHY is in its lowest power (P3) state, and therefore does not provide
> a clock.
> >>>>>>> The Power Down Scale field specifies how many suspend_clk
> >>>>>>> periods fit into a 16 kHz clock period. When performing the
> >>>>>>> division, round up the remainder.
> >>>>>>> For example, when using an 8-bit/16-bit/32-bit PHY and 25-MHz
> >>>>>>> Suspend clock, Power Down Scale = 25000 kHz/16 kHz = 13'd1563
> >>>>>>> (rounder up)
> >>>>>>> Note:
> >>>>>>> - Minimum Suspend clock frequency is 32 kHz
> >>>>>>> - Maximum Suspend clock frequency is 125 MHz"
> >>>>>> Cool, now do we have an upper bound for how many clock cycles it
> >>>>>> takes to wake up the PHY?
> >>>>> My understanding is this ep command does not wake up the SS PHY,
> >>>>> the SS PHY still stays at P3 when execute this ep command. The
> >>>>> time required here is to wait controller complete something for
> >>>>> this ep command with 32K clock.
> >>>> Sorry I made a mistake. You're right. Just checked with one of the
> >>>> RTL engineers, and it doesn't need to wake up the phy. However, if
> >>>> it is eSS speed, it may take longer time as the command may be
> >>>> completing with the suspend clock.
> >>>>
> >>> What's the value for GCTL[7:6]?
> >> 2'b00
> >>
> >> Thanks
> >> Li Jun
> > (Sorry for the delay reply)
> >
> > If it's 0, then the ram clock should be the same as the bus_clk, which
> > is odd since you mentioned that the suspend_clk is used instead while in P3.
> 
> Just checked with the RTL engineer, even if GCTL[7:6] is set to 0, internally it
> can still run with suspend clock during P3.

Thanks for your check.
> 
> > Anyway, I was looking for a way maybe to improve the speed during
> > issuing a command. One way is to set GUSB3PIPECTL[17]=0, and it should
> > wakeup the phy anytime. I think Felipe suggested it. It's odd that it
> > doesn't work for you. I don't have other ideas beside increasing the
> > command timeout.
> >
> 
> In any case, increasing the timeout should be fine with me. It maybe difficult to
> determine the max timeout base on the slowest clock rate and number of cycles.
> Different controller and controller versions behave differently and may have
> different number of clock cycles to complete a command.
> 
> The RTL engineer recommended timeout to be at least 1ms (which maybe more than the
> polling rate of this patch). I'm fine with either the rate provided by this tested
> patch or higher.

OK, I will change the timeout to be 1ms if no object from Felipe.

thanks
Li Jun
> 
> BR,
> Thinh

  parent reply	other threads:[~2020-05-21  7:33 UTC|newest]

Thread overview: 53+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-28 21:59 [PATCH v4 0/9] Prereqs for HiKey960 USB support John Stultz
2019-10-28 21:59 ` [PATCH v4 1/9] dt-bindings: usb: rt1711h: Add connector bindings John Stultz
2019-10-28 21:59 ` [PATCH v4 2/9] usb: dwc3: Execute GCTL Core Soft Reset while switch modes John Stultz
2019-10-29  9:09   ` Felipe Balbi
2019-10-29 21:21     ` John Stultz
2019-10-28 21:59 ` [PATCH v4 3/9] usb: dwc3: Increase timeout for CmdAct cleared by device controller John Stultz
2019-10-29  9:11   ` Felipe Balbi
2019-10-29 21:17     ` John Stultz
2020-05-06  9:00       ` Jun Li
2020-05-06 22:27         ` John Stultz
2020-05-07  3:08           ` Jun Li
2020-05-08 12:22             ` Jun Li
2020-05-08 12:35               ` Felipe Balbi
2020-05-09  8:28                 ` Jun Li
2020-05-08 12:33         ` Felipe Balbi
2020-05-09  8:10           ` Jun Li
2020-05-15  9:31             ` Felipe Balbi
2020-05-15 10:07               ` Jun Li
2020-05-15 10:41                 ` Felipe Balbi
2020-05-16  0:25                 ` Thinh Nguyen
2020-05-16  7:12                   ` Felipe Balbi
2020-05-16  9:20                     ` Jun Li
2020-05-16 11:57                       ` Felipe Balbi
2020-05-19  2:24                         ` Jun Li
2020-05-19  6:28                           ` Thinh Nguyen
2020-05-19  6:46                             ` Thinh Nguyen
2020-05-19  7:39                               ` Jun Li
2020-05-21  1:07                                 ` Thinh Nguyen
2020-05-21  1:55                                   ` Thinh Nguyen
2020-05-21  6:20                                     ` Felipe Balbi
2020-05-21  6:22                                       ` Felipe Balbi
2020-05-21  7:47                                         ` Jun Li
2020-05-21  7:33                                     ` Jun Li [this message]
2019-10-28 21:59 ` [PATCH v4 4/9] dt-bindings: usb: dwc3: Allow clock list & resets to be more flexible John Stultz
2019-10-28 21:59 ` [PATCH v4 5/9] usb: dwc3: Rework clock initialization " John Stultz
2019-10-29  9:13   ` Felipe Balbi
2019-10-29 16:08     ` John Stultz
2019-10-30  9:02       ` Felipe Balbi
2019-11-07 21:53     ` Rob Herring
2019-10-28 21:59 ` [PATCH v4 6/9] usb: dwc3: Rework resets " John Stultz
2019-10-29  9:17   ` Felipe Balbi
2019-10-29 18:05     ` John Stultz
2019-10-30  9:01       ` Felipe Balbi
2019-11-07 21:45         ` Rob Herring
2019-10-28 21:59 ` [PATCH v4 7/9] usb: dwc3: Registering a role switch in the DRD code John Stultz
2019-10-29  9:21   ` Felipe Balbi
2019-11-07 23:20     ` John Stultz
2019-10-28 21:59 ` [PATCH v4 8/9] dt-bindings: usb: generic: Add role-switch-default-host binding John Stultz
2019-10-29  9:23   ` Felipe Balbi
2019-10-29 18:26     ` John Stultz
2019-10-28 21:59 ` [PATCH v4 9/9] usb: dwc3: Add host-mode as default support John Stultz
2019-10-29  9:25   ` Felipe Balbi
2019-11-07 22:23     ` John Stultz

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