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| author | Janek Kotas <jank@cadence.com> | 2018-06-04 11:24:44 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-09-09 19:55:53 +0200 |
| commit | e7b6b3699b97a1e6b1ad31cd7c611dd92685c399 (patch) | |
| tree | ade8dd882c00431765d916125a8648b11aebb15d | |
| parent | dc9a7dd57f63e56dcba88565c57cde7b55efb329 (diff) | |
| download | linux-stable-e7b6b3699b97a1e6b1ad31cd7c611dd92685c399.tar.gz linux-stable-e7b6b3699b97a1e6b1ad31cd7c611dd92685c399.tar.bz2 linux-stable-e7b6b3699b97a1e6b1ad31cd7c611dd92685c399.zip | |
spi: cadence: Change usleep_range() to udelay(), for atomic context
commit 931c4e9a72ae91d59c5332ffb6812911a749da8e upstream.
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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/spi/spi-cadence.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/spi/spi-cadence.c b/drivers/spi/spi-cadence.c index 4a001634023e..02bd1eba045b 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++); |