On 9/27/2023 1:46 PM, Greg Kroah-Hartman wrote:
On Wed, Sep 27, 2023 at 01:00:27PM +0530, Krishna Kurapati wrote:
In the event gadget_connect call (which invokes pullup) fails,
propagate the error to udc bind operation which in turn sends the
error to configfs. The userspace can then retry enumeration if
it chooses to.
Will this break userspace that is not expecting error codes to be
returned? What userspace code will now be modified to handle this?
Where is that work happening?
thanks,
Hi Greg,
This only handles cases where the pullup failed but the error code
wasn't returned to configfs_udc_store approrpiately. In userspace when
we do the following:
echo "UDC NAME" > /usb_gadget/<>/UDC
in the issue I was facing, the core soft reset was failing and we return
-110 from dwc3/core.c to udc's bind_to_driver call, but it is not
checked any where today and we return 0 to udc_store in configfs. The
userspace assumes the UDC write went through (and enum happened) but it
actually doesn't. If we propagate the -ETIMEDOUT coming from dwc3-core
all the way to configfs_udc_store, it will reach userspace as well
indicating that the echo command was not successful which then the user
can choose to retry or not. On Android devices, I saw userspace retry
happening when we propagate dwc3-core error to userspace. So nothing in
userspace breaks. It can stay as it but this time, the echo in userspace
will fail if pullup fails for some reason.
Regards,
Krishna,
