Messages in this thread Patch in this message | | | From | Nicholas Mc Guire <> | Subject | [RFC PATCH] mtd: spi-nor: handle signal case as failure | Date | Wed, 3 May 2017 11:53:09 +0200 |
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The problem is that stm32_qspi_wait_cmd() will indicate success in case of being interrupted. The if condition is incomplete here as wait_for_copletion_interruptible_timeout can return -ERESTARTSYS but this is not handled by if(!wait_for_completion_interruptible_timeout()). While somewhat unlikely it probably would be hard to figure out what went wrong if the signal case does occur.
Fixes: commit 0d43d7ab277a ("mtd: spi-nor: add driver for STM32 quad spi flash controller") Signed-off-by: Nicholas Mc Guire <der.herr@hofr.at> --- Problem found by experimental coccinelle script
Its not clear if its sufficient to simply treat this case as failure or if it might need some debug output to allow differentiation of signal and timeout case.
Patch was compile tested with: stm32_defconfig +CONFIG_MTD=y, CONFIG_MTD_SPI_NOR=y, CONFIG_SPI_STM32_QUADSPI=m
Patch is against v4.11-rc8 (localversion-next is next-20170503)
drivers/mtd/spi-nor/stm32-quadspi.c | 10 ++++++++-- 1 files changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/mtd/spi-nor/stm32-quadspi.c b/drivers/mtd/spi-nor/stm32-quadspi.c index 1056e74..27147ad 100644 --- a/drivers/mtd/spi-nor/stm32-quadspi.c +++ b/drivers/mtd/spi-nor/stm32-quadspi.c @@ -159,6 +159,7 @@ static int stm32_qspi_wait_cmd(struct stm32_qspi *qspi) { u32 cr; int err = 0; + long timeout = 0; if (readl_relaxed(qspi->io_base + QUADSPI_SR) & SR_TCF) return 0; @@ -167,8 +168,13 @@ static int stm32_qspi_wait_cmd(struct stm32_qspi *qspi) cr = readl_relaxed(qspi->io_base + QUADSPI_CR); writel_relaxed(cr | CR_TCIE, qspi->io_base + QUADSPI_CR); - if (!wait_for_completion_interruptible_timeout(&qspi->cmd_completion, - msecs_to_jiffies(1000))) + timeout = wait_for_completion_interruptible_timeout( + &qspi->cmd_completion, msecs_to_jiffies(1000)); + + /* since the calling side only cares about success of failure + * returning -ETIMEDOUT even when interrupted should be ok here + */ + if (timeout == 0 || timeout == -ERESTARTSYS) err = -ETIMEDOUT; writel_relaxed(cr, qspi->io_base + QUADSPI_CR); -- 2.1.4
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