From 5442dcaa0d90fc376bdfc179a018931a8f43dea4 Mon Sep 17 00:00:00 2001 From: Chris Lesiak Date: Thu, 7 Mar 2019 20:39:00 +0000 Subject: spi: Fix zero length xfer bug This fixes a bug for messages containing both zero length and unidirectional xfers. The function spi_map_msg will allocate dummy tx and/or rx buffers for use with unidirectional transfers when the hardware can only do a bidirectional transfer. That dummy buffer will be used in place of a NULL buffer even when the xfer length is 0. Then in the function __spi_map_msg, if he hardware can dma, the zero length xfer will have spi_map_buf called on the dummy buffer. Eventually, __sg_alloc_table is called and returns -EINVAL because nents == 0. This fix prevents the error by not using the dummy buffer when the xfer length is zero. Signed-off-by: Chris Lesiak Signed-off-by: Mark Brown --- drivers/spi/spi.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/spi/spi.c') diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 93986f879b09..2be394d3bc59 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -1039,6 +1039,8 @@ static int spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg) if (max_tx || max_rx) { list_for_each_entry(xfer, &msg->transfers, transfer_list) { + if (!xfer->len) + continue; if (!xfer->tx_buf) xfer->tx_buf = ctlr->dummy_tx; if (!xfer->rx_buf) -- cgit v1.2.3 From 1723fdec5fcbc4de3d26bbb23a9e1704ee258955 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Wed, 3 Apr 2019 16:46:56 +0200 Subject: spi: Add missing error handling for CS GPIOs While devm_gpiod_get_index_optional() returns NULL if the GPIO is not present (i.e. -ENOENT), it may still return other error codes, like -EPROBE_DEFER. Currently these are not handled, leading to unrecoverable failures later in case of probe deferral: gpiod_set_consumer_name: invalid GPIO (errorpointer) gpiod_direction_output: invalid GPIO (errorpointer) gpiod_set_value_cansleep: invalid GPIO (errorpointer) gpiod_set_value_cansleep: invalid GPIO (errorpointer) gpiod_set_value_cansleep: invalid GPIO (errorpointer) Detect and propagate errors to fix this. Fixes: f3186dd876697e69 ("spi: Optionally use GPIO descriptors for CS GPIOs") Signed-off-by: Geert Uytterhoeven Signed-off-by: Mark Brown --- drivers/spi/spi.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/spi/spi.c') diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 2be394d3bc59..7b6494bd8a9b 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -2197,6 +2197,8 @@ static int spi_get_gpio_descs(struct spi_controller *ctlr) */ cs[i] = devm_gpiod_get_index_optional(dev, "cs", i, GPIOD_OUT_LOW); + if (IS_ERR(cs[i])) + return PTR_ERR(cs[i]); if (cs[i]) { /* -- cgit v1.2.3