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author | Ben Whitten <ben.whitten@gmail.com> | 2016-11-14 15:13:20 +0000 |
---|---|---|
committer | Mark Brown <broonie@kernel.org> | 2016-11-15 18:51:35 +0000 |
commit | 39fe33f98b64501f5816f743c052215e7f66700b (patch) | |
tree | e936993c3f9cfa8719453b554154b70a6a4c1924 /drivers/spi/spi-atmel.c | |
parent | 9610620078a3900e7fad82de620ce809fd29ba60 (diff) | |
download | lwn-39fe33f98b64501f5816f743c052215e7f66700b.tar.gz lwn-39fe33f98b64501f5816f743c052215e7f66700b.zip |
spi: atmel: Fix scheduling while atomic
A call to clk_get_rate appears to be called in the context of an interrupt,
cache the bus clock for the frequency calculations in transmission.
This fixes a 'BUG: scheduling while atomic' and
'WARNING: CPU: 0 PID: 777 at kernel/sched/core.c:2960 atmel_spi_unlock'
Signed-off-by: Ben Whitten <ben.whitten@lairdtech.com>
Signed-off-by: Steve deRosier <steve.derosier@lairdtech.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi/spi-atmel.c')
-rw-r--r-- | drivers/spi/spi-atmel.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c index d3affa6afe7e..9fb00ac3ac2e 100644 --- a/drivers/spi/spi-atmel.c +++ b/drivers/spi/spi-atmel.c @@ -296,6 +296,7 @@ struct atmel_spi { int irq; struct clk *clk; struct platform_device *pdev; + unsigned long spi_clk; struct spi_transfer *current_transfer; int current_remaining_bytes; @@ -865,7 +866,7 @@ static int atmel_spi_set_xfer_speed(struct atmel_spi *as, unsigned long bus_hz; /* v1 chips start out at half the peripheral bus speed. */ - bus_hz = clk_get_rate(as->clk); + bus_hz = as->spi_clk; if (!atmel_spi_is_v2(as)) bus_hz /= 2; @@ -1634,6 +1635,9 @@ static int atmel_spi_probe(struct platform_device *pdev) ret = clk_prepare_enable(clk); if (ret) goto out_free_irq; + + as->spi_clk = clk_get_rate(clk); + spi_writel(as, CR, SPI_BIT(SWRST)); spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */ if (as->caps.has_wdrbt) { |