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| author | Janek Kotas <jank@cadence.com> | 2018-06-04 11:24:44 +0000 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2018-06-18 13:05:38 +0100 |
| commit | 931c4e9a72ae91d59c5332ffb6812911a749da8e (patch) | |
| tree | 56617fddc08509eaa19f4e4dc90741e72c2f1c79 /drivers/spi | |
| parent | 08ba7ae35b15cd13b965d5fd5a835e0a0cb803e6 (diff) | |
| download | linux-931c4e9a72ae91d59c5332ffb6812911a749da8e.tar.gz | |
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
Diffstat (limited to 'drivers/spi')
| -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 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++); |