[PATCH 5/5] usb: typec: ucsi: Clear UCSI_CCI_RESET_COMPLETE before reset

Christian A. Ehrhardt
2024-03-20T07:40:18Z

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>
---
drivers/usb/typec/ucsi/ucsi.c | 36 ++++++++++++++++++++++++++++++++++-
1 file changed, 35 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
index 63f340dbd867..85e507df7fa8 100644
--- a/drivers/usb/typec/ucsi/ucsi.c
+++ b/drivers/usb/typec/ucsi/ucsi.c
@@ -1264,13 +1264,47 @@ static int ucsi_reset_connector(struct ucsi_connector *con, bool hard)

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)
--
2.40.1