Musb host suspend on Omap3530 question

Tomas zheng

Intellectual 270 points

Other Parts Discussed in Thread: OMAP3530, SYSCONFIG

Hi Ajay & Swami,

I am using Omap3530evm Rev D. but not using linux.

My MUSB on Omap3530 works as usb host, on the root hub we have one powered hub with bind of devices such as

two bulk, 2 Keyboard and one hub with 2 mouse. Every thing work fine till now.

But when I plug out the power of the external hub, the Musb host controller will enter into suspend mode.

I know this is the power supply is not enough to stop the host controller.And this scenario can be accepted.

What I want to ask, do you know how can the soft ware to know we are in the suspend mode?

You know there will be no interrupt and I look over all the usb related register not such status registers to show that.

Or any suggestion?

Thanks very much,

Tomas

over 15 years ago

0 Ajay over 15 years ago

TI__Genius 9460 points

Why do you say that musb goes into suspend mode ? As per linux driver, musb switches off bus session whenever disconenct happens. We use to enable

the session again by writing SESSION bit in DevCtl register. Can you try setting this bit after disconnect.

Regards,
Ajay

0 Tomas zheng over 15 years ago in reply to Ajay

Intellectual 270 points

Ajay said:

Why do you say that musb goes into suspend mode ?

>> We can see it suspend use usb analyzer.

>> And if in suspend, we can not get any interrupt, include disconnection interrupt.

As per linux driver, musb switches off bus session whenever disconenct happens. We use to enable

the session again by writing SESSION bit in DevCtl register. Can you try setting this bit after disconnect.

>> when disconnect, restart session is the right way, I have done that. But that can not help with the

>> suspend mode,at least in my case. I am not quit know linux stuff, and also do not know if linux can

>> reproduce such case. I want ask, is there anyway to know the host in the suspend mode, not from

>> the analyzer.

Regards,
Ajay

0 Tomas zheng over 15 years ago in reply to Tomas zheng

Intellectual 270 points

To avoid misunderstanding, I plug out the _power cable_ of external powered hub on the root hub, not the hub.

0 Ajay over 15 years ago in reply to Tomas zheng

TI__Genius 9460 points

When you disconnect the power supply to external hub, that is equivalent to disconnect for musb host. Do you get any disconenct interrupt ?

0 Tomas zheng over 15 years ago in reply to Ajay

Intellectual 270 points

0 Ajay over 15 years ago in reply to Tomas zheng

TI__Genius 9460 points

Can you please provide the value of POWER and DEVCTL register after you disconnect the ext. hub?

0 Tomas zheng over 15 years ago in reply to Ajay

Intellectual 270 points

Hi Ajay,

Disconnect the power of the

Ajay said:

Can you please provide the value of POWER and DEVCTL register after you disconnect the ext. hub?

>> disconnect the external hub

POWER 0x61, DEVCTL 0x19

>> disconnect the power of the external hub

POWER 0x61, DEVCTL 0x5d

0 Ajay over 15 years ago in reply to Tomas zheng

TI__Genius 9460 points

Please do not enable SUSPENDM bit (D0) in POWER register (=0x61). This bit is read only for hardware and is written by your software.

0 Tomas zheng over 15 years ago in reply to Tomas zheng

Intellectual 270 points

Hi Ajay, I can reproduce the disconnect interrupt by another test case. 1. Power up the board 2. plug in one un-powered hub 3. Plug in one usb flopy on the hub Disconnect interrupt comming But also can reproduce suspend mode using usb Flash 1. Power up the board 2. plug in one un-powered hub 3. Plug in one usb Flash on the hub It seems drop too much power can make the host into disconnect interrupt, right? How do you think, do you know any hardware doc describ that? Thanks, Tomas

0 Ajay over 15 years ago in reply to Tomas zheng

TI__Genius 9460 points

Thomas,

Please also provide the register values of OTG_SYSCONFIG (0x404) and OTG_FORCESTDBY (0x414).

Regards,
Ajay

0 Tomas zheng over 15 years ago in reply to Ajay

Intellectual 270 points

Hi Ajay,

Thanks for your suggestion.

I just try to disable ENSUSPM (D0) and SUSPENDM (D1) in POWER, get the same result.

POWER = 0x60 and DEVCTL = 0x5d

Can you explain what function for the two bit ?

My understanding is , SUSPENDM (D1) is the host want to enter to suspend mode, we can set this bit.

ENSUSPM (D0) is to enable this function? is that right?

Thanks,

Tomas

0 Tomas zheng over 15 years ago in reply to Ajay

Intellectual 270 points

Hi Ajay,

It seems the internet is too slow to post on this page.

OTG_SYSCONFIG = 0x2011

TG_FORCESTDBY = 0

Can you explain what you are concern?

Thanks,

Tomas

0 Ajay over 15 years ago in reply to Tomas zheng

TI__Genius 9460 points

Thomas,

Can you test with AUTOIDLE=0 (D0) in OTG_SYSCONFIG and POWER =0x60.

Ajay

0 Tomas zheng over 15 years ago in reply to Ajay

Intellectual 270 points

Hi Ajay,

Thanks again for your kindly suggestion. But reconfigure OTG_SYSCONFIG still not helped us.
It still the same.

Thanks,

Tomas

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Musb host suspend on Omap3530 question