Re: [PATCH] Revert "usb: dwc3: gadget: drop unnecessary loop when cleaning up TRBs"

Hi,

On Mon, Aug 31, 2015 at 08:25:10PM +0300, Ville Syrjälä wrote:

On Mon, Aug 31, 2015 at 11:54:13AM -0500, Felipe Balbi wrote:

quoted

On Mon, Aug 31, 2015 at 07:48:28PM +0300, ville.syrjala@linux.intel.com wrote:

quoted

From: Ville Syrjälä <redacted>

This reverts commit 8f2c9544aba636134303105ecb164190a39dece4.

As it breaks g_ether on my Baytrail FFRD8 device. Everything starts out
fine, but after a bit of data has been transferred it just stops
flowing.

Note that I do get a bunch of these "NOHZ: local_softirq_pending 08"
when booting the machine, but I'm not really sure if they're related
to this problem.

I have a feeling your problem is elsewhere. We *are* completing one TRB
at a time. By reverting that commit you're just masking the real problem
and I'd rather get that one fixed.

How do you reproduce your issue ?

Just boot the system, it gets an IP from dnsmasq on my host, then I ssh
into it and do something to produce a bit of console output, after which
g_ether is dead. Eg. 'dmesg' a few times is enough to kill it.

which kernel version ? Running as USB2 or USB3 ? Have you tried
linux-next ? I just did 1000 dmesg iterations over ssh with g_ether and
saw no issues.

Can you enable dwc3 tracepoints and try again ? (use some very large
trace buffer, something around 2 or 4 MiB should be enough).

cheers

-- 
balbi