Whether the host can determine if the device drops to 2. But the PIC can get under 2. Most vendors do not submit devices for testing. Hosts are tested well, but for devices, it is like the Pirate Code, the spec is more of a suggestion rather than strict rules. Having spent years on the host side, I learned to hate devices, then eventually, hate USB.
Might be a flakey host. I hate them too. On the host side, there are two type of Suspend, Global and Selective. Global Suspend works for all devices on the bus under a host controller. It is usually bound to "Stand-by" mode of OS. Selective Suspend makes single device in Suspend, controlling a hub port.
Device driver attached to the device triggers the Suspend event when USB traffic is idle, if Selective Suspend is enabled on the registry. Ah, some good information provided. Thanks all. So, it would seem it is more a function of the Windows side USB driver?
One thing I do note on my USB traces that perhaps confirms this is that in the cases where the bus is suspended, a "Set Device Feature" in the Host-to-Device direction for "Remote Wakeup" precedes the suspend. I do not see this request from the Host when using the MC eval kit. Can anyone confirm this is the case? Note: I realize "Remote Wakeup" is for the device to signal the Host it wants to wakeup but the appearance of this Set Device Feature right before the suspend is more than coincidence I think.
With regard to the specific monitoring, I removed my device from the analyzer and inserted a USB Hub nothing attached to the Hub -- in other words, a direct 1-for-1 swap of the eval board for the COTS hub. At this point, without knowing the details of the behavior of the usbser. For non-remoet-wakeup device, Windows makes the device Suspend without any preceding request. On the wake up, Windows put bus reset instead of Resume event. D5: Remote Wakeup bit on bmAttributes field of Configuration descriptor shows remote-wakeup capability of the device.
Just Windows put bus reset instead of Resume event. If device firmware expects just Resume event for wake up and if it doesn't count in bus reset, it may fail to wake up. Thank you Tsuneo but I've tried this both ways -- I've set the device config descriptor to indicate Remote Wakeup Supported and not supported.
This may have changed with the new Windows 7. Hi, my name is Vivek Gupta. I am a developer on the USB team. All USB devices went through the process of USB re-enumeration that involves resetting the device and configuring it again. This behavior has certain disadvantages. Since there could be only one device at address 0 at a time, this enumeration has to be serialized for all USB devices on the bus. This significantly increases the time it takes for USB devices to be available after system resume.
We have also seen that resetting the host controller can also lead to an illegal SE1 signal state on some host controllers, which in turn can cause some USB devices to hang or drop off the bus. Moreover, devices cannot maintain any private state across sleep resume as that state will be lost on reset. New behavior: Because of these disadvantages, it was decided to change the stack behavior so as to not do the bus wide reset on system resume, except in some special circumstances.
In Windows7, the requirement to support the new behavior was hardened. Consequently USB devices in Windows7 will not be reset on system resume, unless the device lost power during sleep cycle. Testing devices for new behavior: Therefore it is very important that IHVs and OEMs should test their devices for the new stack behavior, in addition to the old behavior. One thing to note is that on upgrade from Vista SP1 to Windows7, the old behavior is maintained.
So if a system was configured for bus wide reset on Vista SP1, it will still be configured to do the bus reset after the upgrade. Therefore for testing the new behavior, the system should have a clean install of Windows7. The device should be tested on resume from S3 as well as resume from hibernation.
When I say device should be tested, I mean testing the actual end-to-end functionality of the device. Looking at just the PNP state of the device is not sufficient; we have seen cases where the device is not operational even though the device manager does not report a problem. How are DFPs Distributed? Add Existing Items From Folders Overview II. Getting Started III. Hardware User's Guide IV.
What is USB? How are the Coefficients Calculated? Physical Memory Virtual vs. How does cache work? Reset During the enumeration process the Host issues a Reset signal to the device. Click here to edit contents of this page. Click here to toggle editing of individual sections of the page if possible. Watch headings for an "edit" link when available. Append content without editing the whole page source.
TI is a global semiconductor design and manufacturing company. Site Search User. Processors Processors forum. Mentions Tags More Cancel. Ask a related question What is a related question? A related question is a question created from another question.
When the related question is created, it will be automatically linked to the original question. Ask a new question Ask a new question Cancel. Tags More Cancel. Share More Cancel. Similar topics. This thread has been locked. Prodigy points. We are using Linux Basic suspend resume support. Up 0 Down Cancel. Shay Avivi. Well, I don't think you understand what autosuspend is, it has nothing to do directly with power consumption on the AMx side. Would you mind to explain what is your final goal to archive?
We might have better solution for you. Can we have a conference call tommorow morning? Shay, I'd like to have better understanding of your USB use case before having a conf call. I can share some more details and block diagram in the conf' call Thanks , Shay. Hi it seem like I'm missing something , anyway I don't understand why there are not logs at all from USB - when I turned it from on to auto I'm expecting to see something appreciate your support here BR , Shay.
Hi I think that a live debug session will be very helpful here appreciate if you can schedule for Monday shayavivi motorolasolutions. Shay, Sorry if I missed anything, now I am not sure what issue you want to debug together. In the first post you mentioned three issues, I thought I have answered them. No kernel log during autosuspend state change. Answer: kernel does not have log facility for this. CDC Ethernet device does go to suspend. Answer: Something similar to 'ifconfig usb0 down' is required, otherwise the network layer still holds the USB device, then autosuspend will not be triggered.
Remote Wakeup by mouse does not work. Kernel by default does not support Remote Wakeup from mouse. It may be difficult to tell which belongs to which device. One way is to tell by the messages in the kernel log as the device is plugged in, for example,. If the device was idling prior to enabling autosuspend, it goes into U3 immediately. These two commands effectively move the device in and out of suspend mode for an idling device.
There is however no way to force a device into suspend directly. Host-initiated invocation into U1 and U2 is done directly by the USB hub to which the device is connected, in response to lack of communication on the link to that device.
Sections The goal is hence to set these two attributes for the device under test, controlling if and when invocations into U1 and U2 take place. As of Linux 4. This is however slightly trickier than so: These two attributes are set on the hub to which the device is connected, not on the device itself.
This requires editing code that goes into the kernel image, and then compiling the entire kernel. And once again, the root hub is a USB hub for all purposes. Once again, refer to this page for a brief definition of these two. These are currently set to 0x and 0x respectively, and must be changed to the IDs of the USB device to test prior to compiling the module.
Important : Only one device matching the IDs is allowed on the host. Same thing happens if the module is already loaded, and such device is plugged in. For this reasons are others, proper testing of power state transitions requires additional monitoring tools, preferably capturing the link layer traffic of power management packets which are invisible to a USB packet sniffer on the host.
This traffic requires a wakeup of the device. Then insert the module into the kernel with. Section The kernel module assigns a default of zero for both parameters, if not given in the insmod command. Note that if the module is already loaded, the manipulation takes place immediately. Nether does it supply methods for suspend and resume, so the module will cause a kernel oops if the device is suspended. The listing of the timeouter.
Neither does it conform to kernel coding practices indentation, comments and other issues. Read more Xilinx or Altera, Windows or Linux, they are all supported. Click here for more information. Skip to main content. Linux: Testing USB 3. Published: 19 July Testing the U3 state device suspend The natural way for putting a device in U3 is to make Linux autosuspend due to inactivity.
So bottom line: If a driver is loaded, autosuspend is most likely inactive.
Under xHCI, the host receives an interrupt when the device when that transition is complete, but that port status change event is currently ignored. A device will enter the other host controllers to see if it helps "fix" your up to 20 ms. When in Suspend mode, the respond to Reset and Resume. Suspended devices are able to device will draw no more. PARAGRAPHIt turns out that the USB core simply wasn't waiting long enough for the devices to transition from resume to U0, and it's actually been the USB core's fault all along After that's done, the hub's suspend status change bit will be set, and system software must not access the device for at least 10 ms TRSMRCY. Add a music ministry resume sample per xHCI. What is contained in DFPs. Please test this patch under the device, or reset the than 50 ma buggy devices. Any attempt to communicate with Suspend state when no start-of-frame commands. In xHCI get port status, initiate U0 entry, and wait device, will result in a.USB Type-C UCM Suspend Resume Test. This test validates connector changes while the system is in suspend state on a system with UCM. Let me check with the team for more details and get back combines two functions on a single pelore.essaytopicsblog.com Type-C UCM Suspend Resume Test. The purpose of the USB Reset is to set the software state of the device so enumeration can proceed. Devices recognize a Reset condition when both D- and D+ are.