diff options
| author | David Brownell <david-b@pacbell.net> | 2006-04-03 22:49:04 (GMT) |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2006-05-16 21:33:57 (GMT) |
| commit | a020ed7521a9737bcf3e34eb880867c60c3c68d0 (patch) | |
| tree | 52941e00b05df6c1bfe228fd193fdb09cf963d15 /drivers | |
| parent | ccf77cc4af5b048e20cfd9327fcc286cb69c34cc (diff) | |
| download | linux-a020ed7521a9737bcf3e34eb880867c60c3c68d0.tar.xz | |
[PATCH] SPI: busnum == 0 needs to work
We need to be able to have a "SPI bus 0" matching chip numbering; but
that number was wrongly used to flag dynamic allocation of a bus number.
This patch resolves that issue; now negative numbers trigger dynamic alloc.
It also updates the how-to-write-a-controller-driver overview to mention
this stuff.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/spi/spi.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 1168ef0..7a3f733 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -395,7 +395,7 @@ EXPORT_SYMBOL_GPL(spi_alloc_master); int __init_or_module spi_register_master(struct spi_master *master) { - static atomic_t dyn_bus_id = ATOMIC_INIT(0); + static atomic_t dyn_bus_id = ATOMIC_INIT((1<<16) - 1); struct device *dev = master->cdev.dev; int status = -ENODEV; int dynamic = 0; @@ -404,7 +404,7 @@ spi_register_master(struct spi_master *master) return -ENODEV; /* convention: dynamically assigned bus IDs count down from the max */ - if (master->bus_num == 0) { + if (master->bus_num < 0) { master->bus_num = atomic_dec_return(&dyn_bus_id); dynamic = 1; } |