4.19-stable review patch. If anyone has any objections, please let me know.
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From: Clark Wang xiaoning.wang@nxp.com
[ Upstream commit 77736a98b859e2c64aebbd0f90b2ce4b17682396 ]
Add a error info when set a speed which greater than half of per-clk of spi module.
The minimum SCK period is 2 cycles(CCR[SCKDIV]). So the maximum transfer speed is half of spi per-clk.
Signed-off-by: Clark Wang xiaoning.wang@nxp.com Signed-off-by: Mark Brown broonie@kernel.org Stable-dep-of: 730bbfaf7d48 ("spi: spi-fsl-lpspi: Fix scldiv calculation") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/spi/spi-fsl-lpspi.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-)
diff --git a/drivers/spi/spi-fsl-lpspi.c b/drivers/spi/spi-fsl-lpspi.c index 5802f188051b8..8e1f6ee0a7993 100644 --- a/drivers/spi/spi-fsl-lpspi.c +++ b/drivers/spi/spi-fsl-lpspi.c @@ -263,6 +263,13 @@ static int fsl_lpspi_set_bitrate(struct fsl_lpspi_data *fsl_lpspi) u8 prescale;
perclk_rate = clk_get_rate(fsl_lpspi->clk_per); + + if (config.speed_hz > perclk_rate / 2) { + dev_err(fsl_lpspi->dev, + "per-clk should be at least two times of transfer speed"); + return -EINVAL; + } + for (prescale = 0; prescale < 8; prescale++) { scldiv = perclk_rate / (clkdivs[prescale] * config.speed_hz) - 2; @@ -316,7 +323,7 @@ static int fsl_lpspi_config(struct fsl_lpspi_data *fsl_lpspi) return 0; }
-static void fsl_lpspi_setup_transfer(struct spi_device *spi, +static int fsl_lpspi_setup_transfer(struct spi_device *spi, struct spi_transfer *t) { struct fsl_lpspi_data *fsl_lpspi = @@ -349,7 +356,7 @@ static void fsl_lpspi_setup_transfer(struct spi_device *spi, else fsl_lpspi->watermark = fsl_lpspi->txfifosize;
- fsl_lpspi_config(fsl_lpspi); + return fsl_lpspi_config(fsl_lpspi); }
static int fsl_lpspi_slave_abort(struct spi_controller *controller) @@ -428,7 +435,10 @@ static int fsl_lpspi_transfer_one_msg(struct spi_controller *controller, msg->actual_length = 0;
list_for_each_entry(xfer, &msg->transfers, transfer_list) { - fsl_lpspi_setup_transfer(spi, xfer); + ret = fsl_lpspi_setup_transfer(spi, xfer); + if (ret < 0) + goto complete; + fsl_lpspi_set_cmd(fsl_lpspi, is_first_xfer);
is_first_xfer = false;