Unverified Commit 04b2d03a authored by Geert Uytterhoeven's avatar Geert Uytterhoeven Committed by Mark Brown
Browse files

spi: Fix double IDR allocation with DT aliases 



If the SPI bus number is provided by a DT alias, idr_alloc() is called
twice, leading to:

    WARNING: CPU: 1 PID: 1 at drivers/spi/spi.c:2179 spi_register_controller+0x11c/0x5d8
    couldn't get idr

Fix this by moving the handling of fixed SPI bus numbers up, before the
DT handling code fills in ctlr->bus_num.

Fixes: 1a4327fb ("spi: fix IDR collision on systems with both fixed and dynamic SPI bus numbers")
Signed-off-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Tested-by: default avatarFabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 1a4327fb

drivers/spi/spi.c

+11 −11
Original line number Diff line number Diff line
@@ -2143,8 +2143,17 @@ int spi_register_controller(struct spi_controller *ctlr) 
	 */

	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);

		id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,

			ctlr->bus_num + 1, GFP_KERNEL);

		mutex_unlock(&board_lock);

		if (WARN(id < 0, "couldn't get idr"))

			return id == -ENOSPC ? -EBUSY : id;

		ctlr->bus_num = id;

	} else if (ctlr->dev.of_node) {

		/* allocate dynamic bus number using Linux idr */

	if ((ctlr->bus_num < 0) && ctlr->dev.of_node) {

		id = of_alias_get_id(ctlr->dev.of_node, "spi");

		if (id >= 0) {

			ctlr->bus_num = id;
@@ -2170,15 +2179,6 @@ int spi_register_controller(struct spi_controller *ctlr) 
		if (WARN(id < 0, "couldn't get idr"))

			return id;

		ctlr->bus_num = id;

	} else {

		/* devices with a fixed bus num must check-in with the num */

		mutex_lock(&board_lock);

		id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,

			ctlr->bus_num + 1, GFP_KERNEL);

		mutex_unlock(&board_lock);

		if (WARN(id < 0, "couldn't get idr"))

			return id == -ENOSPC ? -EBUSY : id;

		ctlr->bus_num = id;

	}

	INIT_LIST_HEAD(&ctlr->queue);

	spin_lock_init(&ctlr->queue_lock);

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