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author | Stefan Richter <stefanr@s5r6.in-berlin.de> | 2010-02-20 22:24:43 +0100 |
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committer | Stefan Richter <stefanr@s5r6.in-berlin.de> | 2010-02-20 22:33:13 +0100 |
commit | 4a9bde9b8ab55a2bb51b57cad215a97bcf80bae2 (patch) | |
tree | e36282d7ed7e39f499e93f413cad57897477c53f /drivers/firewire/core-cdev.c | |
parent | 1c1517efe173599ca2f1526ce7a04521cd424a9f (diff) | |
download | linux-stable-4a9bde9b8ab55a2bb51b57cad215a97bcf80bae2.tar.gz linux-stable-4a9bde9b8ab55a2bb51b57cad215a97bcf80bae2.tar.bz2 linux-stable-4a9bde9b8ab55a2bb51b57cad215a97bcf80bae2.zip |
firewire: get_cycle_timer optimization and cleanup
ohci: Break out of the retry loop if too many attempts were necessary.
This may theoretically happen if the chip is fatally defective or if the
get_cycle_timer ioctl was performed after a CardBus controller was
ejected.
Also micro-optimize the loop by re-using the last two register reads in
the next iteration, remove a questionable inline keyword, and shuffle a
comment around.
core: ioctl_get_cycle_timer() is always called with interrupts on,
therefore local_irq_save() can be replaced by local_irq_disable().
Disabled local IRQs imply disabled preemption, hence preempt_disable()
can be removed.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Diffstat (limited to 'drivers/firewire/core-cdev.c')
-rw-r--r-- | drivers/firewire/core-cdev.c | 16 |
1 files changed, 7 insertions, 9 deletions
diff --git a/drivers/firewire/core-cdev.c b/drivers/firewire/core-cdev.c index e6d63849e78e..ecd0a4d81abf 100644 --- a/drivers/firewire/core-cdev.c +++ b/drivers/firewire/core-cdev.c @@ -25,6 +25,7 @@ #include <linux/firewire.h> #include <linux/firewire-cdev.h> #include <linux/idr.h> +#include <linux/irqflags.h> #include <linux/jiffies.h> #include <linux/kernel.h> #include <linux/kref.h> @@ -32,7 +33,6 @@ #include <linux/module.h> #include <linux/mutex.h> #include <linux/poll.h> -#include <linux/preempt.h> #include <linux/sched.h> #include <linux/spinlock.h> #include <linux/time.h> @@ -1013,21 +1013,19 @@ static int ioctl_get_cycle_timer(struct client *client, void *buffer) { struct fw_cdev_get_cycle_timer *request = buffer; struct fw_card *card = client->device->card; - unsigned long long bus_time; struct timeval tv; - unsigned long flags; + u32 cycle_time; - preempt_disable(); - local_irq_save(flags); + local_irq_disable(); - bus_time = card->driver->get_bus_time(card); + cycle_time = card->driver->get_bus_time(card); do_gettimeofday(&tv); - local_irq_restore(flags); - preempt_enable(); + local_irq_enable(); request->local_time = tv.tv_sec * 1000000ULL + tv.tv_usec; - request->cycle_timer = bus_time & 0xffffffff; + request->cycle_timer = cycle_time; + return 0; } |