The patch

spi: cadence: Change usleep_range() to udelay(), for atomic context

has been applied to the spi tree at

https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git

All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying to this mail.

Thanks, Mark

From 931c4e9a72ae91d59c5332ffb6812911a749da8e Mon Sep 17 00:00:00 2001

From: Janek Kotas jank@cadence.com Date: Mon, 4 Jun 2018 11:24:44 +0000 Subject: [PATCH] spi: cadence: Change usleep_range() to udelay(), for atomic context

The path "spi: cadence: Add usleep_range() for cdns_spi_fill_tx_fifo()" added a usleep_range() function call, which cannot be used in atomic context. However the cdns_spi_fill_tx_fifo() function can be called during an interrupt which may result in a kernel panic:

BUG: scheduling while atomic: grep/561/0x00010002 Modules linked in: Preemption disabled at: [<ffffff800858ea28>] wait_for_common+0x48/0x178 CPU: 0 PID: 561 Comm: grep Not tainted 4.17.0 #1 Hardware name: Cadence CSP (DT) Call trace: dump_backtrace+0x0/0x198 show_stack+0x14/0x20 dump_stack+0x8c/0xac __schedule_bug+0x6c/0xb8 __schedule+0x570/0x5d8 schedule+0x34/0x98 schedule_hrtimeout_range_clock+0x98/0x110 schedule_hrtimeout_range+0x10/0x18 usleep_range+0x64/0x98 cdns_spi_fill_tx_fifo+0x70/0xb0 cdns_spi_irq+0xd0/0xe0 __handle_irq_event_percpu+0x9c/0x128 handle_irq_event_percpu+0x34/0x88 handle_irq_event+0x48/0x78 handle_fasteoi_irq+0xbc/0x1b0 generic_handle_irq+0x24/0x38 __handle_domain_irq+0x84/0xf8 gic_handle_irq+0xc4/0x180

This patch replaces the function call with udelay() which can be used in an atomic context, like an interrupt.

Signed-off-by: Jan Kotas jank@cadence.com Signed-off-by: Mark Brown broonie@kernel.org Cc: stable@vger.kernel.org --- drivers/spi/spi-cadence.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/spi/spi-cadence.c b/drivers/spi/spi-cadence.c index f3dad6fcdc35..a568f35522f9 100644 --- a/drivers/spi/spi-cadence.c +++ b/drivers/spi/spi-cadence.c @@ -319,7 +319,7 @@ static void cdns_spi_fill_tx_fifo(struct cdns_spi *xspi) */ if (cdns_spi_read(xspi, CDNS_SPI_ISR) & CDNS_SPI_IXR_TXFULL) - usleep_range(10, 20); + udelay(10);

if (xspi->txbuf) cdns_spi_write(xspi, CDNS_SPI_TXD, *xspi->txbuf++);