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authorBen Whitten <ben.whitten@gmail.com>2016-11-14 15:13:20 +0000
committerMark Brown <broonie@kernel.org>2016-11-15 18:51:35 +0000
commit39fe33f98b64501f5816f743c052215e7f66700b (patch)
treee936993c3f9cfa8719453b554154b70a6a4c1924 /drivers/spi/spi-atmel.c
parent9610620078a3900e7fad82de620ce809fd29ba60 (diff)
downloadlwn-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.c6
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) {