From: Arnd Bergmann arnd@arndb.de
[ Upstream commit e50989527faeafb79f45a0f7529ba8e01dff1fff ]
Building this file with clang leads to a an unreachable code path causing a warning from objtool:
drivers/spi/spi-rockchip.o: warning: objtool: rockchip_spi_transfer_one()+0x2e0: sibling call from callable instruction with modified stack frame
Change the unreachable() into an error return that can be handled if it ever happens, rather than silently crashing the kernel.
Fixes: 65498c6ae241 ("spi: rockchip: support 4bit words") Signed-off-by: Arnd Bergmann arnd@arndb.de Acked-by: Pratyush Yadav p.yadav@ti.com Link: https://lore.kernel.org/r/20210226140109.3477093-1-arnd@kernel.org Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/spi/spi-rockchip.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/drivers/spi/spi-rockchip.c b/drivers/spi/spi-rockchip.c index 09d8e92400eb..0e2c377e9e55 100644 --- a/drivers/spi/spi-rockchip.c +++ b/drivers/spi/spi-rockchip.c @@ -476,7 +476,7 @@ static int rockchip_spi_prepare_dma(struct rockchip_spi *rs, return 1; }
-static void rockchip_spi_config(struct rockchip_spi *rs, +static int rockchip_spi_config(struct rockchip_spi *rs, struct spi_device *spi, struct spi_transfer *xfer, bool use_dma, bool slave_mode) { @@ -521,7 +521,9 @@ static void rockchip_spi_config(struct rockchip_spi *rs, * ctlr->bits_per_word_mask, so this shouldn't * happen */ - unreachable(); + dev_err(rs->dev, "unknown bits per word: %d\n", + xfer->bits_per_word); + return -EINVAL; }
if (use_dma) { @@ -554,6 +556,8 @@ static void rockchip_spi_config(struct rockchip_spi *rs, */ writel_relaxed(2 * DIV_ROUND_UP(rs->freq, 2 * xfer->speed_hz), rs->regs + ROCKCHIP_SPI_BAUDR); + + return 0; }
static size_t rockchip_spi_max_transfer_size(struct spi_device *spi) @@ -577,6 +581,7 @@ static int rockchip_spi_transfer_one( struct spi_transfer *xfer) { struct rockchip_spi *rs = spi_controller_get_devdata(ctlr); + int ret; bool use_dma;
WARN_ON(readl_relaxed(rs->regs + ROCKCHIP_SPI_SSIENR) && @@ -596,7 +601,9 @@ static int rockchip_spi_transfer_one(
use_dma = ctlr->can_dma ? ctlr->can_dma(ctlr, spi, xfer) : false;
- rockchip_spi_config(rs, spi, xfer, use_dma, ctlr->slave); + ret = rockchip_spi_config(rs, spi, xfer, use_dma, ctlr->slave); + if (ret) + return ret;
if (use_dma) return rockchip_spi_prepare_dma(rs, ctlr, xfer);