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spi: fix IDR collision on systems with both fixed and dynamic SPI bus numbers

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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: 9b61e30221 (spi: Pick spi bus number from Linux idr or spi alias)
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Lucas Stach 2017-10-16 12:27:58 +02:00 committed by Mark Brown
parent 2bd6bf03f4
commit 226584aedd
1 changed files with 9 additions and 4 deletions
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13
drivers/spi/spi.c
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@ -45,7 +45,6 @@
#define CREATE_TRACE_POINTS
#include <trace/events/spi.h>
#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;