From: Ivan T. Ivanov <iivanov@mm-sol.com>
Date: Thu, 20 Feb 2014 10:02:08 +0000 (+0200)
Subject: spi: core: Validate length of the transfers in message
X-Git-Tag: MMI-PSA29.97-13-9~12508^2~9^2~4
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=4d94bd21b333;p=GitHub%2FMotorolaMobilityLLC%2Fkernel-slsi.git

spi: core: Validate length of the transfers in message

SPI transfer length should be multiple of SPI word size,
where SPI word size should be power-of-two multiple

Signed-off-by: Ivan T. Ivanov <iivanov@mm-sol.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
---

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index bb660145d19e..1b53eee2cbca 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 % w_size)
+			return -EINVAL;
+
 		if (xfer->speed_hz && master->min_speed_hz &&
 		    xfer->speed_hz < master->min_speed_hz)
 			return -EINVAL;