| Message ID | 20221120153704.9090-3-ftoth@exalondelft.nl (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | usb: dwc3: core: defer probe on ulpi_read_id timeout | expand |
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.
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c index 648f1c570021..2779f17bffaf 100644 --- a/drivers/usb/dwc3/core.c +++ b/drivers/usb/dwc3/core.c @@ -1106,8 +1106,13 @@ static int dwc3_core_init(struct dwc3 *dwc) if (!dwc->ulpi_ready) { ret = dwc3_core_ulpi_init(dwc); - if (ret) + if (ret) { + if (ret == -ETIMEDOUT) { + dwc3_core_soft_reset(dwc); + ret = -EPROBE_DEFER; + } goto err0; + } dwc->ulpi_ready = true; }
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> --- drivers/usb/dwc3/core.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)