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Subject[PATCH v2] spi: core: Validate lenght of the transfers in message
Date
From: "Ivan T. Ivanov" <iivanov@mm-sol.com>

SPI transfer lenght should be a power-of-two multiple
of eight bits.

Signed-off-by: Ivan T. Ivanov <iivanov@mm-sol.com>
---
drivers/spi/spi.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index d0b28bb..9bed365 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -1617,6 +1617,7 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message)
{
struct spi_master *master = spi->master;
struct spi_transfer *xfer;
+ int w_size, n_words;

if (list_empty(&message->transfers))
return -EINVAL;
@@ -1668,6 +1669,22 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message)
return -EINVAL;
}

+ /*
+ * SPI transfer length should be multiple of SPI word size
+ * where SPI word size should be power-of-two multiple
+ */
+ if (xfer->bits_per_word <= 8)
+ w_size = 1;
+ else if (xfer->bits_per_word <= 16)
+ w_size = 2;
+ else
+ w_size = 4;
+
+ n_words = xfer->len / w_size;
+ /* No partial transfers accepted */
+ if (!n_words || xfer->len % xfer->bits_per_word)
+ return -EINVAL;
+
if (xfer->speed_hz && master->min_speed_hz &&
xfer->speed_hz < master->min_speed_hz)
return -EINVAL;
--
1.7.9.5


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