From mboxrd@z Thu Jan 1 00:00:00 1970 From: nicolas.ferre@atmel.com (Nicolas Ferre) Date: Mon, 14 Nov 2016 16:18:42 +0100 Subject: [PATCH RESEND] spi: atmel: Fix scheduling while atomic In-Reply-To: <1479136400-10285-1-git-send-email-ben.whitten@lairdtech.com> References: <1479136400-10285-1-git-send-email-ben.whitten@lairdtech.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Le 14/11/2016 ? 16:13, Ben Whitten a ?crit : > 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 > Signed-off-by: Steve deRosier Acked-by: Nicolas Ferre > --- > > Resending due to missing off the subsystem maintainer in initial submission, > pointed out by Alexandre Belloni, thanks. BTW, it's actually more a "v2" than a "RESEND". Thanks a lot for your patch. Best regards, > --- > drivers/spi/spi-atmel.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c > index 8feac59..c281d1a 100644 > --- a/drivers/spi/spi-atmel.c > +++ b/drivers/spi/spi-atmel.c > @@ -295,6 +295,7 @@ 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; > @@ -864,7 +865,7 @@ 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; > > @@ -1606,6 +1607,9 @@ 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) { > -- Nicolas Ferre