Since commit 0f010171
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() on the first test write failing
with -ETIMEDOUT. Currently ulpi_read_id() expects to discover the phy via
DT when the test write fails and returns 0 in that case even if DT does not
provide the phy. Due to the timeout being masked dwc3 probe continues by
calling dwc3_core_soft_reset() followed by dwc3_get_extcon() which happens
to return -EPROBE_DEFER. On deferred probe ulpi_read_id() finally succeeds.
This patch changes ulpi_read_id() to return -ETIMEDOUT when it occurs and
catches the error in dwc3_core_init(). It handles the error by calling
dwc3_core_soft_reset() after which it requests -EPROBE_DEFER. On deferred
probe ulpi_read_id() again succeeds.
Signed-off-by: Ferry Toth <ftoth@xxxxxxxxxxxxxx>
---
drivers/usb/common/ulpi.c | 5 +++--
drivers/usb/dwc3/core.c | 5 ++++-
2 files changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/common/ulpi.c b/drivers/usb/common/ulpi.c
index d7c8461976ce..d8f22bc2f9d0 100644
--- a/drivers/usb/common/ulpi.c
+++ b/drivers/usb/common/ulpi.c
@@ -206,8 +206,9 @@ static int ulpi_read_id(struct ulpi *ulpi)
/* Test the interface */
ret = ulpi_write(ulpi, ULPI_SCRATCH, 0xaa);
- if (ret < 0)
- goto err;
+ if (ret < 0) {
+ return ret;
+ }
ret = ulpi_read(ulpi, ULPI_SCRATCH);
if (ret < 0)
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 648f1c570021..e293ef70039b 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -1106,8 +1106,11 @@ static int dwc3_core_init(struct dwc3 *dwc)
if (!dwc->ulpi_ready) {
ret = dwc3_core_ulpi_init(dwc);
- if (ret)
+ if (ret) {
+ dwc3_core_soft_reset(dwc);
+ ret = -EPROBE_DEFER;
goto err0;
+ }
dwc->ulpi_ready = true;
}
--
2.34.1
