[PATCH 6.6 377/396] usb: typec: ucsi: Clear UCSI_CCI_RESET_COMPLETE before reset

Greg Kroah-Hartman
2024-04-01T16:55:11Z

From: Christian A. Ehrhardt <lk@c--e.de>

commit 3de4f996a0b5412aa451729008130a488f71563e upstream.

Check the UCSI_CCI_RESET_COMPLETE complete flag before starting
another reset. Use a UCSI_SET_NOTIFICATION_ENABLE command to clear
the flag if it is set.

Signed-off-by: Christian A. Ehrhardt <lk@c--e.de>
Cc: stable <stable@kernel.org>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8550-QRD
Link: https://lore.kernel.org/r/20240320073927.1641788-6-lk@c--e.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/usb/typec/ucsi/ucsi.c | 36 +++++++++++++++++++++++++++++++++++-
1 file changed, 35 insertions(+), 1 deletion(-)

--- a/drivers/usb/typec/ucsi/ucsi.c
+++ b/drivers/usb/typec/ucsi/ucsi.c
@@ -982,13 +982,47 @@ static int ucsi_reset_connector(struct u

static int ucsi_reset_ppm(struct ucsi *ucsi)
{
- u64 command = UCSI_PPM_RESET;
+ u64 command;
unsigned long tmo;
u32 cci;
int ret;

mutex_lock(&ucsi->ppm_lock);

+ ret = ucsi->ops->read(ucsi, UCSI_CCI, &cci, sizeof(cci));
+ if (ret < 0)
+ goto out;
+
+ /*
+ * If UCSI_CCI_RESET_COMPLETE is already set we must clear
+ * the flag before we start another reset. Send a
+ * UCSI_SET_NOTIFICATION_ENABLE command to achieve this.
+ * Ignore a timeout and try the reset anyway if this fails.
+ */
+ if (cci & UCSI_CCI_RESET_COMPLETE) {
+ command = UCSI_SET_NOTIFICATION_ENABLE;
+ ret = ucsi->ops->async_write(ucsi, UCSI_CONTROL, &command,
+ sizeof(command));
+ if (ret < 0)
+ goto out;
+
+ tmo = jiffies + msecs_to_jiffies(UCSI_TIMEOUT_MS);
+ do {
+ ret = ucsi->ops->read(ucsi, UCSI_CCI,
+ &cci, sizeof(cci));
+ if (ret < 0)
+ goto out;
+ if (cci & UCSI_CCI_COMMAND_COMPLETE)
+ break;
+ if (time_is_before_jiffies(tmo))
+ break;
+ msleep(20);
+ } while (1);
+
+ WARN_ON(cci & UCSI_CCI_RESET_COMPLETE);
+ }
+
+ command = UCSI_PPM_RESET;
ret = ucsi->ops->async_write(ucsi, UCSI_CONTROL, &command,
sizeof(command));
if (ret < 0)