From b953296de73ac75bb380a609f9f30e9fe34e7622 Mon Sep 17 00:00:00 2001
From: xueyanhong <xueyanhong@xiaomi.com>
Date: Thu, 27 Jan 2022 19:02:06 +0800
Subject: [PATCH] input/buttons: Fix the event lose between the invocation of
 poll

Signed-off-by: xueyanhong <xueyanhong@xiaomi.com>
---
 drivers/input/button_upper.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/drivers/input/button_upper.c b/drivers/input/button_upper.c
index ecb669a6e6..3d84c0abd1 100644
--- a/drivers/input/button_upper.c
+++ b/drivers/input/button_upper.c
@@ -95,6 +95,7 @@ struct btn_open_s
    * driver events.
    */
 
+  bool bo_pending;
   FAR struct pollfd *bo_fds[CONFIG_INPUT_BUTTONS_NPOLLWAITERS];
 };
 
@@ -281,6 +282,10 @@ static void btn_sample(FAR struct btn_upperhalf_s *priv)
 
   for (opriv = priv->bu_open; opriv; opriv = opriv->bo_flink)
     {
+      /* Always set bo_pending true, only clear it after button read */
+
+      opriv->bo_pending = true;
+
       /* Have any poll events occurred? */
 
       if ((press & opriv->bo_pollevents.bp_press)     != 0 ||
@@ -488,11 +493,13 @@ static ssize_t btn_read(FAR struct file *filep, FAR char *buffer,
                         size_t len)
 {
   FAR struct inode *inode;
+  FAR struct btn_open_s *opriv;
   FAR struct btn_upperhalf_s *priv;
   FAR const struct btn_lowerhalf_s *lower;
   int ret;
 
   DEBUGASSERT(filep && filep->f_inode);
+  opriv = filep->f_priv;
   inode = filep->f_inode;
   DEBUGASSERT(inode->i_private);
   priv  = (FAR struct btn_upperhalf_s *)inode->i_private;
@@ -523,6 +530,7 @@ static ssize_t btn_read(FAR struct file *filep, FAR char *buffer,
   lower = priv->bu_lower;
   DEBUGASSERT(lower && lower->bl_buttons);
   *(FAR btn_buttonset_t *)buffer = lower->bl_buttons(lower);
+  opriv->bo_pending = false;
 
   btn_givesem(&priv->bu_exclsem);
   return (ssize_t)sizeof(btn_buttonset_t);
@@ -759,6 +767,19 @@ static int btn_poll(FAR struct file *filep, FAR struct pollfd *fds,
 
               opriv->bo_fds[i] = fds;
               fds->priv = &opriv->bo_fds[i];
+
+              /* Report if the event is pending */
+
+              if (opriv->bo_pending)
+                {
+                  fds->revents |= (fds->events & POLLIN);
+                  if (fds->revents != 0)
+                    {
+                      iinfo("Report events: %02x\n", fds->revents);
+                      nxsem_post(fds->sem);
+                    }
+                }
+
               break;
             }
         }