commit 2372f1caec upstream.
Currently gadget_wakeup() waits for U0 synchronously if it was
called from func_wakeup(), this is because we need to send the
function wakeup command soon after the link is active. And the
call is made synchronous by polling DSTS continuosly for 20000
times in __dwc3_gadget_wakeup(). But it observed that sometimes
the link is not active even after polling 20K times, leading to
remote wakeup failures. Adding a small delay between each poll
helps, but that won't guarantee resolution in future. Hence make
the gadget_wakeup completely asynchronous.
Since multiple interfaces can issue a function wakeup at once,
add a new variable wakeup_pending_funcs which will indicate the
functions that has issued func_wakup, this is represented in a
bitmap format. If the link is in U3, dwc3_gadget_func_wakeup()
will set the bit corresponding to interface_id and bail out.
Once link comes back to U0, linksts_change irq is triggered,
where the function wakeup command is sent based on bitmap.
Cc: stable <stable@kernel.org>
Fixes: 92c08a84b5 ("usb: dwc3: Add function suspend and function wakeup support")
Signed-off-by: Prashanth K <prashanth.k@oss.qualcomm.com>
Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/20250422103231.1954387-4-prashanth.k@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
f6fdbe4d54