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>
diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
index d3affa6..9fb00ac 100644
--- a/drivers/spi/spi-atmel.c
+++ b/drivers/spi/spi-atmel.c
@@ -296,6 +296,7 @@
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 @@
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 @@
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) {