On Sun, Nov 20, 2022 at 04:37:04PM +0100, Ferry Toth wrote:
Since commit 0f0101719138 ("usb: dwc3: Don't switch OTG -> peripheral if extcon is present"), Dual Role support on Intel Merrifield platform broke due to rearranging the call to dwc3_get_extcon().
It appears to be caused by ulpi_read_id() masking the timeout on the first test write. In the past dwc3 probe continued by calling dwc3_core_soft_reset() followed by dwc3_get_extcon() which happend to return -EPROBE_DEFER. On deferred probe ulpi_read_id() finally succeeded. Due to above mentioned rearranging -EPROBE_DEFER is not returned and probe completes without phy.
As we now changed ulpi_read_id() to return -ETIMEDOUT in this case, we need to handle the error by calling dwc3_core_soft_reset() and request -EPROBE_DEFER. On deferred probe ulpi_read_id() is retried and succeeds.
Fixes: ef6a7bcfb01c ("usb: ulpi: Support device discovery via DT") Cc: stable@vger.kernel.org
Signed-off-by: Ferry Toth ftoth@exalondelft.nl
Same comments as per patch 1.
But before sending v5, let give a chance to others to review the code and other aspects of the changes.