From 1ff7760ff66b98ef244bf0e5e2bd5310651205ad Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Tue, 12 Apr 2016 12:58:14 +0100 Subject: [PATCH] spi: spi-ti-qspi: Handle truncated frames properly We clamp frame_len_words to a maximum of 4096, but do not actually limit the number of words written or read through the DATA registers or the length added to spi_message::actual_length. This results in silent data corruption for commands longer than this maximum. Recalculate the length of each transfer, taking frame_len_words into account. Use this length in qspi_{read,write}_msg(), and to increment spi_message::actual_length. Signed-off-by: Ben Hutchings Signed-off-by: Mark Brown Cc: stable@vger.kernel.org --- drivers/spi/spi-ti-qspi.c | 32 ++++++++++++++++++++------------ 1 file changed, 20 insertions(+), 12 deletions(-) diff --git a/drivers/spi/spi-ti-qspi.c b/drivers/spi/spi-ti-qspi.c index 0ee4139dec48..443f664534e1 100644 --- a/drivers/spi/spi-ti-qspi.c +++ b/drivers/spi/spi-ti-qspi.c @@ -236,16 +236,16 @@ static inline int ti_qspi_poll_wc(struct ti_qspi *qspi) return -ETIMEDOUT; } -static int qspi_write_msg(struct ti_qspi *qspi, struct spi_transfer *t) +static int qspi_write_msg(struct ti_qspi *qspi, struct spi_transfer *t, + int count) { - int wlen, count, xfer_len; + int wlen, xfer_len; unsigned int cmd; const u8 *txbuf; u32 data; txbuf = t->tx_buf; cmd = qspi->cmd | QSPI_WR_SNGL; - count = t->len; wlen = t->bits_per_word >> 3; /* in bytes */ xfer_len = wlen; @@ -305,9 +305,10 @@ static int qspi_write_msg(struct ti_qspi *qspi, struct spi_transfer *t) return 0; } -static int qspi_read_msg(struct ti_qspi *qspi, struct spi_transfer *t) +static int qspi_read_msg(struct ti_qspi *qspi, struct spi_transfer *t, + int count) { - int wlen, count; + int wlen; unsigned int cmd; u8 *rxbuf; @@ -324,7 +325,6 @@ static int qspi_read_msg(struct ti_qspi *qspi, struct spi_transfer *t) cmd |= QSPI_RD_SNGL; break; } - count = t->len; wlen = t->bits_per_word >> 3; /* in bytes */ while (count) { @@ -355,12 +355,13 @@ static int qspi_read_msg(struct ti_qspi *qspi, struct spi_transfer *t) return 0; } -static int qspi_transfer_msg(struct ti_qspi *qspi, struct spi_transfer *t) +static int qspi_transfer_msg(struct ti_qspi *qspi, struct spi_transfer *t, + int count) { int ret; if (t->tx_buf) { - ret = qspi_write_msg(qspi, t); + ret = qspi_write_msg(qspi, t, count); if (ret) { dev_dbg(qspi->dev, "Error while writing\n"); return ret; @@ -368,7 +369,7 @@ static int qspi_transfer_msg(struct ti_qspi *qspi, struct spi_transfer *t) } if (t->rx_buf) { - ret = qspi_read_msg(qspi, t); + ret = qspi_read_msg(qspi, t, count); if (ret) { dev_dbg(qspi->dev, "Error while reading\n"); return ret; @@ -451,7 +452,8 @@ static int ti_qspi_start_transfer_one(struct spi_master *master, struct spi_device *spi = m->spi; struct spi_transfer *t; int status = 0, ret; - unsigned int frame_len_words; + unsigned int frame_len_words, transfer_len_words; + int wlen; /* setup device control reg */ qspi->dc = 0; @@ -484,14 +486,20 @@ static int ti_qspi_start_transfer_one(struct spi_master *master, qspi->cmd = ((qspi->cmd & ~QSPI_WLEN_MASK) | QSPI_WLEN(t->bits_per_word)); - ret = qspi_transfer_msg(qspi, t); + wlen = t->bits_per_word >> 3; + transfer_len_words = min(t->len / wlen, frame_len_words); + + ret = qspi_transfer_msg(qspi, t, transfer_len_words * wlen); if (ret) { dev_dbg(qspi->dev, "transfer message failed\n"); mutex_unlock(&qspi->list_lock); return -EINVAL; } - m->actual_length += t->len; + m->actual_length += transfer_len_words * wlen; + frame_len_words -= transfer_len_words; + if (frame_len_words == 0) + break; } mutex_unlock(&qspi->list_lock); -- 2.20.1