The patch spi: sh-msiof: Fix bit field overflow writes to TSCR/RSCR has been applied to the spi tree at https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted. You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed. If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced. Please add any relevant lists and maintainers to the CCs when replying to this mail. Thanks, Mark >From 10b4640833e95eeacaef8060bc1b35e636df3218 Mon Sep 17 00:00:00 2001 From: Vladimir Zapolskiy <vladimir_zapolskiy@xxxxxxxxxx> Date: Fri, 13 Apr 2018 15:44:16 +0300 Subject: [PATCH] spi: sh-msiof: Fix bit field overflow writes to TSCR/RSCR The change fixes a bit field overflow which allows to write to higher bits while calculating SPI transfer clock and setting BRPS and BRDV bit fields, the problem is reproduced if 'parent_rate' to 'spi_hz' ratio is greater than 1024, for instance p->min_div = 2, MSO rate = 33333333, SPI device rate = 10000 results in k = 5, i.e. BRDV = 0b100 or 1/32 prescaler output, BRPS = 105, TSCR value = 0x6804, thus MSSEL and MSIMM bit fields are non-zero. Fixes: 65d5665bb260 ("spi: sh-msiof: Update calculation of frequency dividing") Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@xxxxxxxxxx> Signed-off-by: Mark Brown <broonie@xxxxxxxxxx> --- drivers/spi/spi-sh-msiof.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/spi/spi-sh-msiof.c b/drivers/spi/spi-sh-msiof.c index ae086aab57d5..8171eedbfc90 100644 --- a/drivers/spi/spi-sh-msiof.c +++ b/drivers/spi/spi-sh-msiof.c @@ -283,6 +283,7 @@ static void sh_msiof_spi_set_clk_regs(struct sh_msiof_spi_priv *p, } k = min_t(int, k, ARRAY_SIZE(sh_msiof_spi_div_table) - 1); + brps = min_t(int, brps, 32); scr = sh_msiof_spi_div_table[k].brdv | SCR_BRPS(brps); sh_msiof_write(p, TSCR, scr); -- 2.17.0
