In order to make request_*muxed_region() behave more like mutex_lock(), a possible failure case needs to be eliminated. When drivers do not properly share the same I/O region, e.g. one is using request_region() and the other is using request_muxed_region(), the kernel didn't warn the user about it. This change modifies IORESOURCE_MUXED behaviour so it always goes to sleep waiting for the resuorce to be freed and the inconsistent resource flag usage is logged with KERN_ERR.
Signed-off-by: Zoltán Böszörményi <[email protected]> --- kernel/resource.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/resource.c b/kernel/resource.c index 220f695..59fa426 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -1150,7 +1150,9 @@ struct resource * __request_declared_region(struct resource *parent, continue; } } - if (conflict->flags & flags & IORESOURCE_MUXED) { + if (flags & IORESOURCE_MUXED) { + if (!(conflict->flags & IORESOURCE_MUXED)) + printk(KERN_ERR "Resource conflict between muxed \"%s\" and non-muxed \"%s\" I/O regions!\n", res->name, conflict->name); add_wait_queue(&muxed_resource_wait, &wait); write_unlock(&resource_lock); set_current_state(TASK_UNINTERRUPTIBLE); -- 2.9.4 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
