(nuttx) branch master updated: arch/arm64/imx9: reject PWM channels outside the timer

[acassis]

This is an automated email from the ASF dual-hosted git repository.

acassis pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/nuttx.git


The following commit(s) were added to refs/heads/master by this push:
     new 6bec3b6f5bf arch/arm64/imx9: reject PWM channels outside the timer
6bec3b6f5bf is described below

commit 6bec3b6f5bf025764d7053ab6927172b917bbcb1
Author: Royyan Zahir <roy...@gmail.com>
AuthorDate: Wed Sep 30 12:18:25 2026 +0400

    arch/arm64/imx9: reject PWM channels outside the timer
    
    A negative channel passed both checks, and TPM took one past the end,
    so a caller could write FlexIO and TPM registers it does not own. TPM
    also dropped the error and reported success.
    
    Signed-off-by: Royyan Zahir <roy...@gmail.com>
---
 arch/arm64/src/imx9/imx9_flexio_pwm.c |  3 ++-
 arch/arm64/src/imx9/imx9_tpm_pwm.c    | 25 ++++++++++++-------------
 2 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/arch/arm64/src/imx9/imx9_flexio_pwm.c 
b/arch/arm64/src/imx9/imx9_flexio_pwm.c
index c1bb241335c..be123a464d1 100644
--- a/arch/arm64/src/imx9/imx9_flexio_pwm.c
+++ b/arch/arm64/src/imx9/imx9_flexio_pwm.c
@@ -393,6 +393,7 @@ static int pwm_select_func_clock(struct imx9_pwmtimer_s 
*priv, int freq)
 static int pwm_update_frequency(struct imx9_pwmtimer_s *priv, int freq)
 {
   int ret = pwm_select_func_clock(priv, freq);
+
   if (ret < 0)
     {
       return ret;
@@ -450,7 +451,7 @@ static int pwm_update_duty(struct imx9_pwmtimer_s *priv, 
int pwm_ch,
   int timer = pwm_ch - 1; /* map pwm ch 1 to timer 0 etc.. */
   uint32_t regval;
 
-  if (pwm_ch == 0 || pwm_ch > priv->nchannels)
+  if (pwm_ch < 1 || pwm_ch > priv->nchannels)
     {
       pwmerr("ERROR: PWM%d has no such channel: %u\n", priv->id, pwm_ch);
       return -EINVAL;
diff --git a/arch/arm64/src/imx9/imx9_tpm_pwm.c 
b/arch/arm64/src/imx9/imx9_tpm_pwm.c
index 9e73f596c43..bfc7884d92d 100644
--- a/arch/arm64/src/imx9/imx9_tpm_pwm.c
+++ b/arch/arm64/src/imx9/imx9_tpm_pwm.c
@@ -439,7 +439,7 @@ static int pwm_update_duty(struct imx9_pwmtimer_s *priv, 
int pwm_ch,
   uint32_t edge = (duty * priv->period + 0x8000) >> 16;
   int timer = pwm_ch - 1;
 
-  if (pwm_ch == 0 || timer > priv->n_channels)
+  if (pwm_ch < 1 || pwm_ch > priv->n_channels)
     {
       pwmerr("ERROR: PWM%d has no such channel: %d\n", priv->id, timer);
       return -EINVAL;
@@ -520,7 +520,7 @@ static int pwm_start(struct pwm_lowerhalf_s *dev,
                      const struct pwm_info_s *info)
 {
   struct imx9_pwmtimer_s *priv = (struct imx9_pwmtimer_s *)dev;
-  int ret = OK;
+  int ret;
   int i;
 
   if (priv == NULL || info == NULL || info->frequency == 0)
@@ -530,20 +530,19 @@ static int pwm_start(struct pwm_lowerhalf_s *dev,
 
   /* Set the frequency if not changed */
 
-  if (pwm_update_frequency(priv, info->frequency) == OK)
-    {
-      /* Handle channel specific setup */
+  ret = pwm_update_frequency(priv, info->frequency);
 
-      for (i = 0; i < CONFIG_PWM_NCHANNELS; i++)
-        {
-          if (ret != OK || info->channels[i].channel == -1)
-            {
-              break;
-            }
+  /* Handle channel specific setup */
 
-          pwm_update_duty(priv, info->channels[i].channel,
-                          info->channels[i].duty);
+  for (i = 0; i < CONFIG_PWM_NCHANNELS; i++)
+    {
+      if (ret != OK || info->channels[i].channel == -1)
+        {
+          break;
         }
+
+      ret = pwm_update_duty(priv, info->channels[i].channel,
+                            info->channels[i].duty);
     }
 
   return ret;