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Remove n from tu_fifo_get_write_info() and fix bug in vendor class

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This commit is contained in:
Reinhard Panhuber
2021-04-30 17:37:14 +02:00
parent 6acfa14fec
commit 5add664874
4 changed files with 16 additions and 33 deletions
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33
src/common/tusb_fifo.c
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@@ -950,11 +950,9 @@ void tu_fifo_get_read_info(tu_fifo_t *f, tu_fifo_buffer_info_t *info)
Returns the length and pointer to which bytes can be written into FIFO in a linear manner.
This is of major interest for DMA transmissions not using circular mode. If a returned length is zero the
corresponding pointer is invalid. The returned length is limited to the number of BYTES n which the user
wants to write into the buffer.
The write pointer does NOT get advanced, use tu_fifo_advance_write_pointer() to do so! If the length
returned is less than n i.e. len<n, then a wrap occurs and you need to execute this function a second
time to get a pointer to the wrapped part!
corresponding pointer is invalid. The returned lengths summed up are the currently free space in the FIFO.
The write pointer does NOT get advanced, use tu_fifo_advance_write_pointer() to do so!
TAKE CARE TO NOT OVERFLOW THE BUFFER MORE THAN TWO TIMES THE FIFO DEPTH - IT CAN NOT RECOVERE OTHERWISE!
@param[in] f
Pointer to FIFO
@param[out] *info
@@ -963,12 +961,12 @@ void tu_fifo_get_read_info(tu_fifo_t *f, tu_fifo_buffer_info_t *info)
Number of ITEMS to write into buffer
*/
/******************************************************************************/
void tu_fifo_get_write_info(tu_fifo_t *f, tu_fifo_buffer_info_t *info, uint16_t n)
void tu_fifo_get_write_info(tu_fifo_t *f, tu_fifo_buffer_info_t *info)
{
uint16_t w = f->wr_idx, r = f->rd_idx;
uint16_t free = _tu_fifo_remaining(f, w, r);
if (free == 0 || n > 2*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
if (free == 0)
{
info->len_lin = 0;
info->len_wrap = 0;
@@ -977,21 +975,6 @@ void tu_fifo_get_write_info(tu_fifo_t *f, tu_fifo_buffer_info_t *info, uint16_t
return;
}
// We need n here because we must enforce the read and write pointers to be not more separated than 2*depth!
if (!f->overwritable)
{
// Not overwritable limit up to full
n = tu_min16(n, free);
}
else if (n >= f->depth)
{
n = f->depth;
// We start writing at the read pointer's position since we fill the complete
// buffer and we do not want to modify the read pointer within a write function!
// This would end up in a race condition with read functions!
w = r;
}
// Get relative pointers
w = get_relative_pointer(f, w);
r = get_relative_pointer(f, r);
@@ -1002,14 +985,14 @@ void tu_fifo_get_write_info(tu_fifo_t *f, tu_fifo_buffer_info_t *info, uint16_t
if (w < r)
{
// Non wrapping case
info->len_lin = tu_min16(n, r-w); // Limit to required length
info->len_lin = r-w; // Limit to required length
info->len_wrap = 0;
info->ptr_wrap = NULL;
}
else
{
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
info->len_lin = f->depth - w;
info->len_wrap = free - info->len_lin; // Remaining length - n already was limited to free or FIFO depth
info->ptr_wrap = f->buffer; // Always start of buffer
}