spi: Check conflicting CS based on spi->chip_select instead of device name (b6fb8d3a) · Commits · 戴 / test

Commit (spi: Use stable dev_name for ACPI enumerated SPI slaves) changed the SPI device naming to be based on ACPI device name instead of carrying bus number and chip select for devices enumerated from ACPI namespace. In case of a buggy BIOS that lists multiple SPI devices sharing the same chip select (even though they should use different) the current code fails to detect that and allows the devices to be added to the bus. Fix this by walking through the bus and comparing spi->chip_select instead of device name. This should work regardless what the device name will be in future. Signed-off-by:

Mika Westerberg <mika.westerberg@linux.intel.com> Acked-by:

Jarkko Nikula <jarkko.nikula@linux.intel.com> Signed-off-by:

Mark Brown <broonie@linaro.org>

drivers/spi/spi.c

+13 −5

Original line number	Diff line number	Diff line
		@@ -370,6 +370,17 @@ static void spi_dev_set_name(struct spi_device *spi)
		spi->chip_select);
		}

		static int spi_dev_check(struct device dev, void data)
		{
		struct spi_device *spi = to_spi_device(dev);
		struct spi_device *new_spi = data;

		if (spi->master == new_spi->master &&
		spi->chip_select == new_spi->chip_select)
		return -EBUSY;
		return 0;
		}

		/**
		* spi_add_device - Add spi_device allocated with spi_alloc_device
		* @spi: spi_device to register
		@@ -384,7 +395,6 @@ int spi_add_device(struct spi_device *spi)
		static DEFINE_MUTEX(spi_add_lock);
		struct spi_master *master = spi->master;
		struct device *dev = master->dev.parent;
		struct device *d;
		int status;

		/* Chipselects are numbered 0..max; validate. */
		@@ -404,12 +414,10 @@ int spi_add_device(struct spi_device *spi)
		*/
		mutex_lock(&spi_add_lock);

		d = bus_find_device_by_name(&spi_bus_type, NULL, dev_name(&spi->dev));
		if (d != NULL) {
		status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
		if (status) {
		dev_err(dev, "chipselect %d already in use\n",
		spi->chip_select);
		put_device(d);
		status = -EBUSY;
		goto done;
		}

Admin message