ASoC: rt5677-spi: Handle over reading when flipping bytes

There is a case when a we want to read a large number of bytes that
require a burst but is not a multiple of the word size (8). When this
happens rt5677_spi_reverse will run off the end of the buffer. The
solution is to tell spi_reverse the actual size of the destination and
stop if we reach it even if we have data left that we read.

Cc: Ben Zhang <benzh@chromium.org>
Signed-off-by: Curtis Malainey <cujomalainey@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Curtis Malainey 2019-05-16 18:43:40 -07:00 committed by Mark Brown
parent f7c4842abf
commit 7b8164c1a2
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@ -101,7 +101,7 @@ static void rt5677_spi_reverse(u8 *dst, u32 dstlen, const u8 *src, u32 srclen)
u32 word_size = min_t(u32, dstlen, 8);
for (w = 0; w < dstlen; w += word_size) {
for (i = 0; i < word_size; i++) {
for (i = 0; i < word_size && i + w < dstlen; i++) {
si = w + word_size - i - 1;
dst[w + i] = si < srclen ? src[si] : 0;
}
@ -152,8 +152,9 @@ int rt5677_spi_read(u32 addr, void *rxbuf, size_t len)
status |= spi_sync(g_spi, &m);
mutex_unlock(&spi_mutex);
/* Copy data back to caller buffer */
rt5677_spi_reverse(cb + offset, t[1].len, body, t[1].len);
rt5677_spi_reverse(cb + offset, len - offset, body, t[1].len);
}
return status;
}