Marc Zyngier wrote at Friday, September 02, 2011 3:51 AM: > On 01/09/11 20:08, Stephen Warren wrote: > > Marc Dietich wrote at Thursday, September 01, 2011 5:14 AM: > >> I'll add Stephen Warren from NVIDIA to the CC list. He has more HW to test on. > > > > Here are the results I found: > > > > Harmony: > > Tegra USB3 -> SMSC9514 hub: NOT affected > > (Unplugging LAN cable, or disabling SMSC9514 LAN driver doesn't change this) ... > I just noticed something else. Harmony is fast *most of the time*. In > about one in 3 reboots, I get the slow behavior. When USB is fast, I > also have I2C interrupts "screaming": > > 85: 294321 0 GIC tegra-i2c > 116: 0 0 GIC tegra-i2c > 118: 98542 0 GIC tps6586x > > This is a couple of seconds after boot. > > When USB is slow, I see the following: > [ 0.385270] tps6586x 3-0034: Chip ID read failed: -121 > [ 0.390584] tps6586x: probe of 3-0034 failed with error -5 > > ... and I2C interrupt is quiet. > > The I2C interrupt handler calls writel(), which does a cache sync. That > would explain the "fast" behavior of Harmony. > > Do you see the same this on your board? Yes, I re-ran the test a few more times and see those exact same symptoms. In a case with the screaming I2C interrupts and fast USB, I then did: echo 3-0034 > /sys/bus/i2c/drivers/tps6586x/unbind (I got a kernel BUG and bash crashed here, but just logged back in) which caused the I2C interrupt handler to stop, then re-ran the test. I then saw the slow USB speed. So, now I think *all* platforms(boards) are affected, right? -- nvpublic -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
