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Message
From: "Gayathri Seshadri" <gaysesh@h...>
Date: Fri, 3 Oct 2003 09:38:18 +0530
Subject: Re: [usb] HOW TO Clear STALL condition?
Hi,
As far as my experience with the USB mass storage protocol, i would
suggest you to do a clear feature endpoint stall to the IN endpoint of the
bulk type. Normally the cbw suggests the expected no. of bytes in one of
its 31 bytes and the bulk IN endpoint if has only lesser to the expected no.
of bytes, it sends a STALL.
As i suggested earlier, you can try "CLEAR_FEATURE"(endpoint stall) for
the bulk in endpoint that stalled.
Let me know if this helped..
Regards,
Gayathri Seshadri.
----- Original Message -----
From: <midas@j...>
To: <usb@o...>
Sent: Thursday, October 02, 2003 1:36 PM
Subject: [usb] HOW TO Clear STALL condition?
> Hi,
> I'm a newbie to USB and USB mass storage devices.
> I have a little trouble with my Cypress SL811HS Host Controller.
> I've got the device to enumerate and I've found all of it's endpoints and
> I'm able to send CBW's to the bulk OUT endpoint and read my data from
> the IN endpoint as well as getting my CSW out from the IN endpoint.
> For certain commands like INQUIRY and REQUEST SENSE I have already
> been able to execute in the following sequence..
> 1. Send CBW to bulk OUT endpoint
> 2. Read DATA from bulk IN endpoint
> 3. Read CSW from bulk IN endpoint.
>
> For commands like READ_10 and READ_CAPACITY use sequence above.
> The device WILL be stalled by host.
> Is this STALL just a handshaking message to differentiate a data
> transfer from a CSW transfer? And how to clear this STALL condition?
> I approciate your help.
>
> i.e.
> Read_Capacity
> Host Device
> OUT_CBW ->
> In ->
> <- Data(1st)
> In ->
> <- Data(2nd)
> In ->
> <- Data(3rd)
> In ->
> <- Data(4th)
> In ->
> <- Data(5th)
> In ->
> <- Data(6th)
> In ->
> STALL -> //How to clear this stall
message
> //and continue getting
the following
> //data?
>
>
>
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