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Change tu_fifo_get_linear_write/read_info() to return a struct

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Compilers always complain that variables set by function via pointer
might be uninitialized so to avoid that return values are now delivered
via struct.
This commit is contained in:
Reinhard Panhuber
2021-04-23 11:48:54 +02:00
parent a98d0217a0
commit 7072f0155e
3 changed files with 51 additions and 47 deletions
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50
src/common/tusb_fifo.c
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@@ -905,7 +905,7 @@ void tu_fifo_advance_read_pointer(tu_fifo_t *f, uint16_t n)
Length of linear part IN ITEMS, if zero corresponding pointer ptr is invalid
*/
/******************************************************************************/
uint16_t tu_fifo_get_linear_read_info(tu_fifo_t *f, uint16_t offset, uint16_t n, void **ptr_lin, uint16_t *len_wrap, void **ptr_wrap)
tu_fifo_linear_wr_info tu_fifo_get_linear_read_info(tu_fifo_t *f, uint16_t offset, uint16_t n)
{
// Operate on temporary values in case they change in between
uint16_t w = f->wr_idx, r = f->rd_idx;
@@ -922,8 +922,10 @@ uint16_t tu_fifo_get_linear_read_info(tu_fifo_t *f, uint16_t offset, uint16_t n,
cnt = f->depth;
}
tu_fifo_linear_wr_info info = {0,0,NULL,NULL};
// Skip beginning of buffer
if (cnt == 0 || offset >= cnt) return 0;
if (cnt == 0 || offset >= cnt) return info;
// Check if we can read something at and after offset - if too less is available we read what remains
cnt -= offset;
@@ -934,26 +936,22 @@ uint16_t tu_fifo_get_linear_read_info(tu_fifo_t *f, uint16_t offset, uint16_t n,
r = get_relative_pointer(f, r, offset);
// Copy pointer to buffer to start reading from
*ptr_lin = &f->buffer[r];
*ptr_wrap = f->buffer;
info.ptr_lin = &f->buffer[r];
info.ptr_wrap = f->buffer;
// Check if there is a wrap around necessary
uint16_t len;
if (w > r) {
// Non wrapping case
len = w - r;
len = tu_min16(n, len); // Limit to required length
*len_wrap = 0;
info.len_lin = tu_min16(n, w - r); // Limit to required length
info.len_wrap = 0;
}
else
{
len = f->depth - r; // Also the case if FIFO was full
len = tu_min16(n, len);
*len_wrap = n-len; // n was already limited to what is available
info.len_lin = tu_min16(n, f->depth - r); // Also the case if FIFO was full
info.len_wrap = n-info.len_lin; // n was already limited to what is available
}
return len;
return info;
}
/******************************************************************************/
@@ -979,11 +977,13 @@ uint16_t tu_fifo_get_linear_read_info(tu_fifo_t *f, uint16_t offset, uint16_t n,
Length of linear part IN ITEMS, if zero corresponding pointer ptr is invalid
*/
/******************************************************************************/
uint16_t tu_fifo_get_linear_write_info(tu_fifo_t *f, uint16_t offset, uint16_t n, void **ptr_lin, uint16_t *len_wrap, void **ptr_wrap)
tu_fifo_linear_wr_info tu_fifo_get_linear_write_info(tu_fifo_t *f, uint16_t offset, uint16_t n)
{
uint16_t w = f->wr_idx, r = f->rd_idx;
uint16_t free = _tu_fifo_remaining(f, w, r);
tu_fifo_linear_wr_info info = {0,0,NULL,NULL};
if (!f->overwritable)
{
// Not overwritable limit up to full
@@ -992,7 +992,7 @@ uint16_t tu_fifo_get_linear_write_info(tu_fifo_t *f, uint16_t offset, uint16_t n
else if (n >= f->depth)
{
// If overwrite is allowed it must be less than or equal to 2 x buffer length, otherwise the overflow can not be resolved by the read functions
TU_VERIFY(n <= 2*f->depth);
if(n > 2*f->depth) return info;
n = f->depth;
// We start writing at the read pointer's position since we fill the complete
@@ -1002,31 +1002,27 @@ uint16_t tu_fifo_get_linear_write_info(tu_fifo_t *f, uint16_t offset, uint16_t n
}
// Check if there is room to write to
if (free == 0 || offset >= free) return 0;
if (free == 0 || offset >= free) return info;
// Get relative pointers
w = get_relative_pointer(f, w, offset);
r = get_relative_pointer(f, r, 0);
// Copy pointer to buffer to start writing to
*ptr_lin = &f->buffer[w];
*ptr_wrap = f->buffer; // Always start of buffer
uint16_t len;
info.ptr_lin = &f->buffer[w];
info.ptr_wrap = f->buffer; // Always start of buffer
if (w < r)
{
// Non wrapping case
len = r-w;
len = tu_min16(n, len); // Limit to required length
*len_wrap = 0;
info.len_lin = tu_min16(n, r-w); // Limit to required length
info.len_wrap = 0;
}
else
{
len = f->depth - w;
len = tu_min16(n, len); // Limit to required length
*len_wrap = n-len; // Remaining length - n already was limited to free or FIFO depth
info.len_lin = tu_min16(n, f->depth - w); // Limit to required length
info.len_wrap = n-info.len_lin; // Remaining length - n already was limited to free or FIFO depth
}
return len;
return info;
}