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authorStefan Wahren <wahrenst@gmx.net>2024-09-30 11:30:54 +0200
committerMark Brown <broonie@kernel.org>2024-09-30 22:31:39 +0100
commitfa8ecda9876ac1e7b29257aa82af1fd0695496e2 (patch)
treeb0f034f408f8bacf0b276aebdb76fc7ce3b7ff54 /drivers/spi
parent9852d85ec9d492ebef56dc5f229416c925758edc (diff)
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spi: spi-fsl-lpspi: Adjust type of scldiv
The target value of scldiv is just a byte, but its calculation in fsl_lpspi_set_bitrate could be negative. So use an adequate type to store the result and avoid overflows. After that this needs range check adjustments, but this should make the code less opaque. Signed-off-by: Stefan Wahren <wahrenst@gmx.net> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20240930093056.93418-2-wahrenst@gmx.net Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/spi-fsl-lpspi.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/spi/spi-fsl-lpspi.c b/drivers/spi/spi-fsl-lpspi.c
index 977e8b55c82b..196cc68f2057 100644
--- a/drivers/spi/spi-fsl-lpspi.c
+++ b/drivers/spi/spi-fsl-lpspi.c
@@ -315,9 +315,10 @@ static void fsl_lpspi_set_watermark(struct fsl_lpspi_data *fsl_lpspi)
static int fsl_lpspi_set_bitrate(struct fsl_lpspi_data *fsl_lpspi)
{
struct lpspi_config config = fsl_lpspi->config;
- unsigned int perclk_rate, scldiv, div;
+ unsigned int perclk_rate, div;
u8 prescale_max;
u8 prescale;
+ int scldiv;
perclk_rate = clk_get_rate(fsl_lpspi->clk_per);
prescale_max = fsl_lpspi->devtype_data->prescale_max;
@@ -338,13 +339,13 @@ static int fsl_lpspi_set_bitrate(struct fsl_lpspi_data *fsl_lpspi)
for (prescale = 0; prescale <= prescale_max; prescale++) {
scldiv = div / (1 << prescale) - 2;
- if (scldiv < 256) {
+ if (scldiv >= 0 && scldiv < 256) {
fsl_lpspi->config.prescale = prescale;
break;
}
}
- if (scldiv >= 256)
+ if (scldiv < 0 || scldiv >= 256)
return -EINVAL;
writel(scldiv | (scldiv << 8) | ((scldiv >> 1) << 16),