queue-5.10/usb-typec-ucsi-clear-ucsi_cci_reset_complete-before-reset.patch

   1 From 3de4f996a0b5412aa451729008130a488f71563e Mon Sep 17 00:00:00 2001
   2 From: "Christian A. Ehrhardt" <lk@c--e.de>
   3 Date: Wed, 20 Mar 2024 08:39:26 +0100
   4 Subject: usb: typec: ucsi: Clear UCSI_CCI_RESET_COMPLETE before reset
   5
   6 From: Christian A. Ehrhardt <lk@c--e.de>
   7
   8 commit 3de4f996a0b5412aa451729008130a488f71563e upstream.
   9
  10 Check the UCSI_CCI_RESET_COMPLETE complete flag before starting
  11 another reset. Use a UCSI_SET_NOTIFICATION_ENABLE command to clear
  12 the flag if it is set.
  13
  14 Signed-off-by: Christian A. Ehrhardt <lk@c--e.de>
  15 Cc: stable <stable@kernel.org>
  16 Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
  17 Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8550-QRD
  18 Link: https://lore.kernel.org/r/20240320073927.1641788-6-lk@c--e.de
  19 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  20 ---
  21  drivers/usb/typec/ucsi/ucsi.c |   36 +++++++++++++++++++++++++++++++++++-
  22  1 file changed, 35 insertions(+), 1 deletion(-)
  23
  24 --- a/drivers/usb/typec/ucsi/ucsi.c
  25 +++ b/drivers/usb/typec/ucsi/ucsi.c
  26 @@ -852,13 +852,47 @@ static int ucsi_reset_connector(struct u
  27
  28  static int ucsi_reset_ppm(struct ucsi *ucsi)
  29  {
  30 -       u64 command = UCSI_PPM_RESET;
  31 +       u64 command;
  32         unsigned long tmo;
  33         u32 cci;
  34         int ret;
  35
  36         mutex_lock(&ucsi->ppm_lock);
  37
  38 +       ret = ucsi->ops->read(ucsi, UCSI_CCI, &cci, sizeof(cci));
  39 +       if (ret < 0)
  40 +               goto out;
  41 +
  42 +       /*
  43 +        * If UCSI_CCI_RESET_COMPLETE is already set we must clear
  44 +        * the flag before we start another reset. Send a
  45 +        * UCSI_SET_NOTIFICATION_ENABLE command to achieve this.
  46 +        * Ignore a timeout and try the reset anyway if this fails.
  47 +        */
  48 +       if (cci & UCSI_CCI_RESET_COMPLETE) {
  49 +               command = UCSI_SET_NOTIFICATION_ENABLE;
  50 +               ret = ucsi->ops->async_write(ucsi, UCSI_CONTROL, &command,
  51 +                                            sizeof(command));
  52 +               if (ret < 0)
  53 +                       goto out;
  54 +
  55 +               tmo = jiffies + msecs_to_jiffies(UCSI_TIMEOUT_MS);
  56 +               do {
  57 +                       ret = ucsi->ops->read(ucsi, UCSI_CCI,
  58 +                                             &cci, sizeof(cci));
  59 +                       if (ret < 0)
  60 +                               goto out;
  61 +                       if (cci & UCSI_CCI_COMMAND_COMPLETE)
  62 +                               break;
  63 +                       if (time_is_before_jiffies(tmo))
  64 +                               break;
  65 +                       msleep(20);
  66 +               } while (1);
  67 +
  68 +               WARN_ON(cci & UCSI_CCI_RESET_COMPLETE);
  69 +       }
  70 +
  71 +       command = UCSI_PPM_RESET;
  72         ret = ucsi->ops->async_write(ucsi, UCSI_CONTROL, &command,
  73                                      sizeof(command));
  74         if (ret < 0)