From 97513162cd6d7ed118aa155b4196e88b3e43ff69 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Tue, 21 Aug 2018 11:53:03 +0200 Subject: [PATCH] spi: Fix double IDR allocation with DT aliases commit 04b2d03a75652bda989de1595048f0501dc0c0a0 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: 1a4327fbf4554d5b ("spi: fix IDR collision on systems with both fixed and dynamic SPI bus numbers") Signed-off-by: Geert Uytterhoeven Tested-by: Fabio Estevam Signed-off-by: Mark Brown Cc: Sudip Mukherjee Cc: Kirill Kapranov Signed-off-by: Greg Kroah-Hartman --- drivers/spi/spi.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 780a32175ec0..670dbb7a8500 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -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);