USB issue on Freescale's i.MX35 3-stack board

Hi Alan,

-----Original Message-----
From: Alan Stern [mailto:stern at rowland.harvard.edu]
Sent: Monday, May 16, 2011 3:49 PM
To: Nguyen Dinh-R00091
Cc: linux-usb at vger.kernel.org; linux-arm-kernel at lists.infradead.org; daniel at caiaq.de;
grant.likely at secretlab.ca; u.kleine-koenig at pengutronix.de; s.hauer at pengutronix.de; Mahadevan Mahesh-
R9AADQ
Subject: Re: USB issue on Freescale's i.MX35 3-stack board

On Mon, 16 May 2011, Nguyen Dinh-R00091 wrote:

quoted

Hi,

On the Freescale i.MX35 3DS board, there is a total of 256MB of DDR2 and the configuration is 128MB

on Chip-select 0 and 128MB on chip-select 1. So physically, the memory is not contiguous, so we boot
up the system with these mem= parameters(mem=128M at 0x80000000 mem=128M at 0x90000000). The system seems to
be operating fine and passes stress testing using memtester and oprofile, except for USB.

quoted

Running a USB copy stress test on USB mass storage between a USB HDD and an SD/MMC card causes the

system to hang. The hang can occur at any time between 10 minutes to 2 hours. The hang is much harder
to re-create if logs or delays are introduced.

Your test involves both the USB and MMC subsystems.  How can you tell
which one is responsible for the hang?

Have you tried testing these subsystems one at a time?

Yes, I've stress tested on USB alone and MMC alone. The issue doesn't seem to appear with a MMC test, but appears when I am moving files between 2 USB HDDs. I apologize for not adding that additional data point on my original email.

Dinh

Alan Stern