Messages in this thread | | | Date | Thu, 19 Apr 2012 13:40:13 -0400 (EDT) | From | Alan Stern <> | Subject | Re: EHCI software retries break Supermicro IPKVM |
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On Thu, 19 Apr 2012, Grzegorz Nosek wrote:
> Hi, > > (Supermicro support: cc'd as you might be interested) > > Commit a2c2706e1043c17139c2dafd171c4a5cf008ef7e introduced software > retries for transient USB errors. Unfortunately, it turns out that > this change breaks the Supermicro AOC SIMSO IPKVM board plugged into > a SYS-6015B-3R server, X7DBR-3 board. It renders unusable both the > keyboard and media redirection as soon as the kernel boots (display > works fine). An excerpt from dmesg: > > [ 76.587521] ehci_hcd 0000:00:1d.7: detected XactErr len 0/8 retry 1 ... > [ 76.591264] ehci_hcd 0000:00:1d.7: detected XactErr len 0/8 retry 31 > [ 76.591388] ehci_hcd 0000:00:1d.7: devpath 7 ep0out 3strikes > [ 76.591402] usb 1-7: can't set config #1, error -71 > [ 76.596519] drivers/usb/core/inode.c: creating file '007' > [ 76.596542] hub 1-0:1.0: state 7 ports 8 chg 0000 evt fe80 > > After disarming the retry logic with the patch below, the KVM works > fine again. Now, this is certainly a crude hack but apparently some > better checks are needed to determine whether to retry the > transaction.
Do you have any idea what's going wrong?
Can you provide complete dmesg logs for kernels both with and without your patch (and with CONFIG_USB_DEBUG enabled)? Maybe also usbmon traces too.
Alan Stern
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