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authorDavid Brownell <david-b@pacbell.net>2006-04-03 15:49:04 -0700
committerGreg Kroah-Hartman <gregkh@suse.de>2006-05-16 14:33:57 -0700
commita020ed7521a9737bcf3e34eb880867c60c3c68d0 (patch)
tree52941e00b05df6c1bfe228fd193fdb09cf963d15 /drivers
parentccf77cc4af5b048e20cfd9327fcc286cb69c34cc (diff)
[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.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 1168ef015887..7a3f733051e9 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;
}