From 226584aedd94acd61ffa51fb69bcf6b3309a7b8f Mon Sep 17 00:00:00 2001 From: Lucas Stach Date: Mon, 16 Oct 2017 12:27:58 +0200 Subject: [PATCH] spi: fix IDR collision on systems with both fixed and dynamic SPI bus numbers On systems where some controllers get a dynamic ID assigned and some have a fixed number from DT, the current implemention might run into an IDR collision if the dynamic controllers gets probed first and get an IDR number, which is later requested by the controller with the fixed numbering. When this happens the fixed controller will fail to register with the SPI core. Fix this by skipping all known alias numbers when assigning the dynamic IDs. Fixes: 9b61e302210e (spi: Pick spi bus number from Linux idr or spi alias) Signed-off-by: Lucas Stach Signed-off-by: Mark Brown --- drivers/spi/spi.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 6e65524..e8b5a5e 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -45,7 +45,6 @@ #define CREATE_TRACE_POINTS #include -#define SPI_DYN_FIRST_BUS_NUM 0 static DEFINE_IDR(spi_master_idr); @@ -2086,7 +2085,7 @@ int spi_register_controller(struct spi_controller *ctlr) struct device *dev = ctlr->dev.parent; struct boardinfo *bi; int status = -ENODEV; - int id; + int id, first_dynamic; if (!dev) return -ENODEV; @@ -2116,9 +2115,15 @@ int spi_register_controller(struct spi_controller *ctlr) } } if (ctlr->bus_num < 0) { + first_dynamic = of_alias_get_highest_id("spi"); + if (first_dynamic < 0) + first_dynamic = 0; + else + first_dynamic++; + mutex_lock(&board_lock); - id = idr_alloc(&spi_master_idr, ctlr, SPI_DYN_FIRST_BUS_NUM, 0, - GFP_KERNEL); + id = idr_alloc(&spi_master_idr, ctlr, first_dynamic, + 0, GFP_KERNEL); mutex_unlock(&board_lock); if (WARN(id < 0, "couldn't get idr")) return id; -- 2.7.4