From 14e2c004cd9db7d386beb2b91804f8e4dfea55f1 Mon Sep 17 00:00:00 2001
From: Reinhard Panhuber <panhuber_reinhard@gmx.at>
Date: Fri, 30 Apr 2021 15:08:14 +0200
Subject: [PATCH] Remove variable n in tu_fifo_get_read_info()

---
 src/class/audio/audio_device.c | 10 ++++++++--
 src/common/tusb_fifo.c         | 10 ++++------
 src/common/tusb_fifo.h         |  2 +-
 3 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/src/class/audio/audio_device.c b/src/class/audio/audio_device.c
index f19f8f6fe..fc5402834 100644
--- a/src/class/audio/audio_device.c
+++ b/src/class/audio/audio_device.c
@@ -985,13 +985,19 @@ static uint16_t audiod_encode_type_I_pcm(uint8_t rhport, audiod_function_t* audi
   {
     dst = &audio->lin_buf_in[cnt_ff*audio->n_channels_per_ff_tx*audio->n_bytes_per_sampe_tx];
 
-    tu_fifo_get_read_info(&audio->tx_supp_ff[cnt_ff], &info, nBytesPerFFToSend);
+    tu_fifo_get_read_info(&audio->tx_supp_ff[cnt_ff], &info);
 
-    if (info.ptr_lin != 0)
+    // Limit up to desired length
+    info.len_lin = tu_min16(nBytesPerFFToSend, info.len_lin);
+
+    if (info.len_lin != 0)
     {
       src_end = info.ptr_lin + info.len_lin;
       dst = audiod_interleaved_copy_bytes_fast_encode(nBytesToCopy, info.ptr_lin, src_end, dst, n_ff_used);
 
+      // Limit up to desired length
+      info.len_wrap = tu_min16(nBytesPerFFToSend - info.len_lin, info.len_wrap);
+
       // Handle wrapped part of FIFO
       if (info.len_wrap != 0)
       {
diff --git a/src/common/tusb_fifo.c b/src/common/tusb_fifo.c
index 92e6bd02c..306b68653 100644
--- a/src/common/tusb_fifo.c
+++ b/src/common/tusb_fifo.c
@@ -896,7 +896,7 @@ void tu_fifo_advance_read_pointer(tu_fifo_t *f, uint16_t n)
                     Pointer to struct which holds the desired infos
  */
 /******************************************************************************/
-void tu_fifo_get_read_info(tu_fifo_t *f, tu_fifo_buffer_info_t *info, uint16_t n)
+void tu_fifo_get_read_info(tu_fifo_t *f, tu_fifo_buffer_info_t *info)
 {
   // Operate on temporary values in case they change in between
   uint16_t w = f->wr_idx, r = f->rd_idx;
@@ -923,8 +923,6 @@ void tu_fifo_get_read_info(tu_fifo_t *f, tu_fifo_buffer_info_t *info, uint16_t n
     return;
   }
 
-  if (cnt < n) n = cnt;
-
   // Get relative pointers
   w = get_relative_pointer(f, w);
   r = get_relative_pointer(f, r);
@@ -935,14 +933,14 @@ void tu_fifo_get_read_info(tu_fifo_t *f, tu_fifo_buffer_info_t *info, uint16_t n
   // Check if there is a wrap around necessary
   if (w > r) {
     // Non wrapping case
-    info->len_lin = tu_min16(n, w - r);            // Limit to required length
+    info->len_lin = cnt;
     info->len_wrap = 0;
     info->ptr_wrap = NULL;
   }
   else
   {
-    info->len_lin = tu_min16(n, f->depth - r);   // Also the case if FIFO was full
-    info->len_wrap = n-info->len_lin;
+    info->len_lin = f->depth - r;                 // Also the case if FIFO was full
+    info->len_wrap = cnt - info->len_lin;
     info->ptr_wrap = f->buffer;
   }
 
diff --git a/src/common/tusb_fifo.h b/src/common/tusb_fifo.h
index 36f0d9302..c6bcdaec5 100644
--- a/src/common/tusb_fifo.h
+++ b/src/common/tusb_fifo.h
@@ -144,7 +144,7 @@ void     tu_fifo_advance_read_pointer   (tu_fifo_t *f, uint16_t n);
 // tu_fifo_advance_read_pointer()/tu_fifo_advance_write_pointer and conduct a second read/write operation
 // TODO - update comments
 
-void tu_fifo_get_read_info(tu_fifo_t *f, tu_fifo_buffer_info_t *info, uint16_t n);
+void tu_fifo_get_read_info(tu_fifo_t *f, tu_fifo_buffer_info_t *info);
 void tu_fifo_get_write_info(tu_fifo_t *f, tu_fifo_buffer_info_t *info, uint16_t n);
 
 static inline uint16_t tu_fifo_depth(tu_fifo_t* f)