From: Stefan Wahren Date: Mon, 30 Sep 2024 09:30:54 +0000 (+0200) Subject: spi: spi-fsl-lpspi: Adjust type of scldiv X-Git-Tag: ceph-for-6.13-rc4~250^2~25^2~2 X-Git-Url: http://git.apps.os.sepia.ceph.com/?a=commitdiff_plain;h=fa8ecda9876ac1e7b29257aa82af1fd0695496e2;p=ceph-client.git 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 Reviewed-by: Frank Li Link: https://patch.msgid.link/20240930093056.93418-2-wahrenst@gmx.net Signed-off-by: Mark Brown --- diff --git a/drivers/spi/spi-fsl-lpspi.c b/drivers/spi/spi-fsl-lpspi.c index 977e8b55c82b7..196cc68f2057b 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),