On 03/07/13 19:55, Frank Rowand wrote: > linux-3.6.11-rt30 builds and boots on some ARM boards (PandaBoard, Realview) for: > > - SMP, PREEMPT_RT_FULL > - SMP, PREEMPT_NONE > - UP, PREEMPT_RT_FULL > - UP, PREEMPT_NONE > > > The PandaBoard frequently fails to boot with an eth0 error. I have > only seen this for SMP, PREEMPT_NONE. This same error also occurs > in 3.6.7 without the RT_PREEMPT patches applied, so this does not > appear to be an RT_PREEMPT issue. > > This error also occurred in the previous smoke test of linux-3.6.7-rt18 > > http://permalink.gmane.org/gmane.linux.rt.user/9202 > > The boot error starts with the USB time out on ep0out: > > [ 3.264373] smsc95xx 1-1.1:1.0: usb_probe_interface > [ 3.269500] smsc95xx 1-1.1:1.0: usb_probe_interface - got id > [ 3.275543] smsc95xx v1.0.4 > [ 8.078674] smsc95xx 1-1.1:1.0: eth0: register 'smsc95xx' at usb-ehci-omap.0-1.1, smsc95xx USB 2.0 Ethernet, 82:b9:1d:fa:67:0d > [ 8.091003] hub 1-1:1.0: state 7 ports 5 chg 0000 evt 0002 > [ 13.509918] usb 1-1.1: swapper/0 timed out on ep0out len=0/4 > [ 13.515869] smsc95xx 1-1.1:1.0: eth0: Failed to write register index 0x00000108 > [ 13.523559] smsc95xx 1-1.1:1.0: eth0: Failed to write ADDRL: -110 > [ 13.529998] IP-Config: Failed to open eth0 > > > The boot error can be avoided with a workaround that simply retries > the failed USB command. I will reply to this email with the patch. > > -Frank panda boot often fails due to a usb timeout, while sending a command on behalf of the smsc95xx ethernet driver. This patch is a temporary hack to force a retry when the timeout occurs. # bad boot: hub 1-1:1.0: state 7 ports 5 chg 0000 evt 0002 usb 1-1.1: swapper timed out on ep0out len=0/4 smsc95xx 1-1.1:1.0: eth0: Failed to write register index 0x00000020 smsc95xx 1-1.1:1.0: eth0: Failed to write PM_CTRL: -110 IP-Config: Failed to open eth0 # good boot: hub 1-1:1.0: state 7 ports 5 chg 0000 evt 0002 usb 1-1.1: link qh8-0001/dc0bae80 start 2 [1/0 us] IP-Config: Complete: device=eth0, addr=192.168.1.85, mask=255.255.255.0, gw=192.168.1.1 host=panda, domain=, nis-domain=(none) bootserver=192.168.1.1, rootserver=192.168.1.1, rootpath= smsc95xx 1-1.1:1.0: eth0: link up, 100Mbps, full-duplex, lpa 0x41E1 VFS: Mounted root (nfs filesystem) on device 0:11. --- drivers/net/usb/smsc95xx.c | 9 8 + 1 - 0 ! 1 file changed, 8 insertions(+), 1 deletion(-) Index: b/drivers/net/usb/smsc95xx.c =================================================================== --- a/drivers/net/usb/smsc95xx.c +++ b/drivers/net/usb/smsc95xx.c @@ -92,6 +92,7 @@ static int smsc95xx_write_reg(struct usb { u32 *buf = kmalloc(4, GFP_KERNEL); int ret; + int retry = 5; BUG_ON(!dev); @@ -101,13 +102,19 @@ static int smsc95xx_write_reg(struct usb *buf = data; cpu_to_le32s(buf); +try_again: ret = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0), USB_VENDOR_REQUEST_WRITE_REGISTER, USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE, 00, index, buf, 4, USB_CTRL_SET_TIMEOUT); - if (unlikely(ret < 0)) + if (unlikely(ret < 0)) { netdev_warn(dev->net, "Failed to write register index 0x%08x\n", index); + if (retry-- && ret == -ETIMEDOUT) { + netdev_warn(dev->net, "failed due to timed out, retrying\n"); + goto try_again; + } + } kfree(buf); -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
