[PATCH] spi: cadence: cache reference clock rate during probe
From: Alexandru Ardelean <hidden>
Date: 2021-01-14 15:39:59
Also in:
lkml
Subsystem:
spi subsystem, the rest · Maintainers:
Mark Brown, Linus Torvalds
From: Michael Hennerich <michael.hennerich@analog.com>
The issue is that using SPI from a callback under the CCF lock will
deadlock, since this code uses clk_get_rate().
Fixes: c474b38665463 ("spi: Add driver for Cadence SPI controller")
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Alexandru Ardelean <redacted>
---
drivers/spi/spi-cadence.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/spi/spi-cadence.c b/drivers/spi/spi-cadence.c
index 70467b9d61ba..a3afd1b9ac56 100644
--- a/drivers/spi/spi-cadence.c
+++ b/drivers/spi/spi-cadence.c@@ -115,6 +115,7 @@ struct cdns_spi { void __iomem *regs; struct clk *ref_clk; struct clk *pclk; + unsigned int clk_rate; u32 speed_hz; const u8 *txbuf; u8 *rxbuf;
@@ -250,7 +251,7 @@ static void cdns_spi_config_clock_freq(struct spi_device *spi, u32 ctrl_reg, baud_rate_val; unsigned long frequency; - frequency = clk_get_rate(xspi->ref_clk); + frequency = xspi->clk_rate; ctrl_reg = cdns_spi_read(xspi, CDNS_SPI_CR);
@@ -558,8 +559,9 @@ static int cdns_spi_probe(struct platform_device *pdev) master->auto_runtime_pm = true; master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH; + xspi->clk_rate = clk_get_rate(xspi->ref_clk); /* Set to default valid value */ - master->max_speed_hz = clk_get_rate(xspi->ref_clk) / 4; + master->max_speed_hz = xspi->clk_rate / 4; xspi->speed_hz = master->max_speed_hz; master->bits_per_word_mask = SPI_BPW_MASK(8);
--
2.17.1