spi: atmel: Fix scheduling while atomic (39fe33f9) · Commits · 戴 / test

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>

drivers/spi/spi-atmel.c

+5 −1

Original line number	Diff line number	Diff line
		@@ -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) {

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