Re: [PATCH v3 3/5] net: asix: Fix AX88772x resume failures

From: Jon Hunter <jonathanh@nvidia.com>
To: <allan@asix.com.tw>, <robert.foss@collabora.com>,
	<freddy@asix.com.tw>, <Dean_Jenkins@mentor.com>,
	<Mark_Craske@mentor.com>, <davem@davemloft.net>,
	<ivecera@redhat.com>, <john.stultz@linaro.org>,
	<vpalatin@chromium.org>, <stephen@networkplumber.org>,
	<grundler@chromium.org>, <changchias@gmail.com>, <andrew@lunn.ch>,
	<tremyfr@gmail.com>, <colin.king@canonical.com>,
	<linux-usb@vger.kernel.org>, <netdev@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>, <vpalatin@google.com>
Subject: Re: [PATCH v3 3/5] net: asix: Fix AX88772x resume failures
Date: Tue, 22 Nov 2016 15:34:01 +0000	[thread overview]
Message-ID: <6aebd7f5-188a-f6b0-7eb0-75b764e069d3@nvidia.com> (raw)
In-Reply-To: <1fff2d2a-7bbe-298c-3d27-7dc44df08675@nvidia.com>

Hi Allan,

On 18/11/16 15:09, Jon Hunter wrote:
> Hi Allan,
> 
> On 14/11/16 09:45, ASIX_Allan [Office] wrote:
>> Hi Jon,
>>
>> Please help to double check if the USB host controller of your Terga
>> platform had been powered OFF while running the ax88772_suspend() routine or
>> not? 
> 
> Sorry for the delay. Today I set up a local board to reproduce this on
> and was able to recreate the same problem. The Tegra xhci driver does
> not power off during suspend and simply calls xhci_suspend(). I also
> checked vbus to see if it was turning off but it is not. Furthermore I
> don't see a new USB device detected after the error and so I don't see
> any evidence that it ever disconnects.

In an attempt to isolate if this is a Tegra issue or not, I recompiled 
v4.9-rc6 for x86 and I was able to reproduce the problem on my desktop ...

[  256.030060] PM: Syncing filesystems ... done.
[  256.113925] PM: Preparing system for sleep (mem)
[  256.114119] Freezing user space processes ... (elapsed 0.002 seconds) done.
[  256.116701] Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done.
[  256.118041] PM: Suspending system (mem)
[  256.118058] Suspending console(s) (use no_console_suspend to debug)
[  256.118324] asix 1-1.2:1.0 eth2: Failed to read reg index 0x0000: -19
[  256.118327] asix 1-1.2:1.0 eth2: Error reading Medium Status register: ffffffed
[  256.118329] asix 1-1.2:1.0 eth2: Failed to write reg index 0x0000: -19
[  256.118332] asix 1-1.2:1.0 eth2: Failed to write Medium Mode mode to 0xfeed: ffffffed
[  256.118374] sd 0:0:0:0: [sda] Synchronizing SCSI cache
[  256.118471] sd 0:0:0:0: [sda] Stopping disk
[  256.152992] hpet1: lost 1 rtc interrupts
[  256.153893] serial 00:06: disabled
[  256.153899] serial 00:06: System wakeup disabled by ACPI
[  256.154068] e1000e: EEE TX LPI TIMER: 00000011
[  256.628281] PM: suspend of devices complete after 509.782 msecs
[  256.628620] PM: late suspend of devices complete after 0.336 msecs
[  256.629366] ehci-pci 0000:00:1d.0: System wakeup enabled by ACPI
[  256.629595] tg3 0000:03:00.0: System wakeup enabled by ACPI
[  256.629601] ehci-pci 0000:00:1a.0: System wakeup enabled by ACPI
[  256.629652] e1000e 0000:00:19.0: System wakeup enabled by ACPI
[  256.629812] xhci_hcd 0000:00:14.0: System wakeup enabled by ACPI
[  256.648347] PM: noirq suspend of devices complete after 19.713 msecs
[  256.648685] ACPI: Preparing to enter system sleep state S3
[  256.668275] PM: Saving platform NVS memory
[  256.668283] Disabling non-boot CPUs ...

To reproduce this, I did the following:

1. Connect the asix device and noted the net interface (ie. eth2)
2. Disabled the interface (ie. sudo ifconfig eth2 down)
3. Ran a suspend-resume cycle using rtcwake (eg. sudo rtcwake -d rtc0 -m mem -s 5)

Cheers
Jon

-- 
nvpublic