Unverified Commit f9481b08 authored Jun 19, 2019 by Tudor Ambarus Committed by Mark Brown Jun 20, 2019

spi: fix ctrl->num_chipselect constraint



at91sam9g25ek showed the following error at probe:
atmel_spi f0000000.spi: Using dma0chan2 (tx) and dma0chan3 (rx)
for DMA transfers
atmel_spi: probe of f0000000.spi failed with error -22

Commit 0a919ae4 ("spi: Don't call spi_get_gpio_descs() before device name is set")
moved the calling of spi_get_gpio_descs() after ctrl->dev is set,
but didn't move the !ctrl->num_chipselect check. When there are
chip selects in the device tree, the spi-atmel driver lets the
SPI core discover them when registering the SPI master.
The ctrl->num_chipselect is thus expected to be set by
spi_get_gpio_descs().

Move the !ctlr->num_chipselect after spi_get_gpio_descs() as it was
before the aforementioned commit. While touching this block, get rid
of the explicit comparison with 0 and update the commenting style.

Fixes: 0a919ae4 ("spi: Don't call spi_get_gpio_descs() before device name is set")
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

parent 51c711f2

drivers/spi/spi.c

+7 −5

Original line number	Diff line number	Diff line
		@@ -2375,11 +2375,6 @@ int spi_register_controller(struct spi_controller *ctlr)
		if (status)
		return status;

		/* even if it's just one always-selected device, there must
		* be at least one chipselect
		*/
		if (ctlr->num_chipselect == 0)
		return -EINVAL;
		if (ctlr->bus_num >= 0) {
		/* devices with a fixed bus num must check-in with the num */
		mutex_lock(&board_lock);
		@@ -2450,6 +2445,13 @@ int spi_register_controller(struct spi_controller *ctlr)
		}
		}

		/*
		* Even if it's just one always-selected device, there must
		* be at least one chipselect.
		*/
		if (!ctlr->num_chipselect)
		return -EINVAL;

		status = device_add(&ctlr->dev);
		if (status < 0) {
		/* free bus id */

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