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spi: Fix double IDR allocation with DT aliases 

commit 04b2d03a75 upstream.

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: 1a4327fbf4 ("spi: fix IDR collision on systems with both fixed and dynamic SPI bus numbers")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Cc: Kirill Kapranov <kirill.kapranov@compulab.co.il>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
pull/10/head
Geert Uytterhoeven 2018-08-21 11:53:03 +02:00 committed by Greg Kroah-Hartman
parent ed5e9462f6
commit 97513162cd
1 changed files with 11 additions and 11 deletions
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22
drivers/spi/spi.c
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@ -2108,8 +2108,17 @@ int spi_register_controller(struct spi_controller *ctlr)
*/
if (ctlr->num_chipselect == 0)
return -EINVAL;
/* allocate dynamic bus number using Linux idr */
if ((ctlr->bus_num < 0) && ctlr->dev.of_node) {
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 */
id = of_alias_get_id(ctlr->dev.of_node, "spi");
if (id >= 0) {
ctlr->bus_num = id;
@ -2135,15 +2144,6 @@ 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);