On Fri, Jul 13, 2018 at 05:33:51PM +0200, Greg Kroah-Hartman wrote:
> On Fri, Jul 13, 2018 at 05:06:37PM +0200, Arnd Bergmann wrote:
> > A new user of the deprecated current_kernel_time() function has appeared
> > here. This code won't work correct during leap seconds or a concurrent
> > settimeofday() call, and it probably doesn't do what the author intended
> > even for the normal case, as it passes a timeout in nanoseconds but
> > reads the time using a jiffies-granularity accessor.
> >
> > I'm changing it to ktime_get_ns() here, which simplifies the logic,
> > and uses a high-res clocksource. This is a bit slower, but that
> > probably doesn't matter in a busy-wait loop.
> >
> > Note: it also doesn't matter in the current version, as there are no
> > callers of this function.
>
> Let's just rip the whole function out, I've been going through and
> removing functions that no one calls and no one uses. That would make
> more sense here. Want me to send a patch for that, or do you want to?
Ah it was easy enough, here's the patch, I'll add it to the longer list
of gasket patches I have queued up to be applied tomorrow:
-------------
From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Subject: [PATCH] staging: gasket: remove gasket_wait_sync()
This function is not called anywhere, so just remove it.
Also, as an added benifit, Arnd points out that it doesn't even work
properly:
This code won't work correct during leap seconds or a concurrent
settimeofday() call, and it probably doesn't do what the author intended
even for the normal case, as it passes a timeout in nanoseconds but
reads the time using a jiffies-granularity accessor.
Reported-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
diff --git a/drivers/staging/gasket/gasket_core.c b/drivers/staging/gasket/gasket_core.c
index 4ca6e53116ea..df52e6e6bf13 100644
--- a/drivers/staging/gasket/gasket_core.c
+++ b/drivers/staging/gasket/gasket_core.c
@@ -2067,50 +2067,6 @@ struct device *gasket_get_device(struct gasket_dev *dev)
return NULL;
}
-/**
- * Synchronously waits on device.
- * @gasket_dev: Device struct.
- * @bar: Bar
- * @offset: Register offset
- * @mask: Register mask
- * @val: Expected value
- * @timeout_ns: Timeout in nanoseconds
- *
- * Description: Busy waits for a specific combination of bits to be set
- * on a Gasket register.
- **/
-int gasket_wait_sync(
- struct gasket_dev *gasket_dev, int bar, u64 offset, u64 mask, u64 val,
- u64 timeout_ns)
-{
- u64 reg;
- struct timespec start_time, cur_time;
- u64 diff_nanosec;
- int count = 0;
-
- reg = gasket_dev_read_64(gasket_dev, bar, offset);
- start_time = current_kernel_time();
- while ((reg & mask) != val) {
- count++;
- cur_time = current_kernel_time();
- diff_nanosec = (u64)(cur_time.tv_sec - start_time.tv_sec) *
- 1000000000LL +
- (u64)(cur_time.tv_nsec) -
- (u64)(start_time.tv_nsec);
- if (diff_nanosec > timeout_ns) {
- gasket_log_error(
- gasket_dev,
- "gasket_wait_sync timeout: reg %llx count %x "
- "dma %lld ns\n",
- offset, count, diff_nanosec);
- return -1;
- }
- reg = gasket_dev_read_64(gasket_dev, bar, offset);
- }
- return 0;
-}
-EXPORT_SYMBOL(gasket_wait_sync);
-
/**
* Asynchronously waits on device.
* @gasket_dev: Device struct.
diff --git a/drivers/staging/gasket/gasket_core.h b/drivers/staging/gasket/gasket_core.h
index 45013446b8c5..e51acadc0fc4 100644
--- a/drivers/staging/gasket/gasket_core.h
+++ b/drivers/staging/gasket/gasket_core.h
@@ -699,11 +699,6 @@ const struct gasket_driver_desc *gasket_get_driver_desc(struct gasket_dev *dev);
/* Get the device structure for a given device. */
struct device *gasket_get_device(struct gasket_dev *dev);
-/* Helper function, Synchronous waits on a given set of bits. */
-int gasket_wait_sync(
- struct gasket_dev *gasket_dev, int bar, u64 offset, u64 mask, u64 val,
- u64 timeout_ns);
-
/* Helper function, Asynchronous waits on a given set of bits. */
int gasket_wait_with_reschedule(
struct gasket_dev *gasket_dev, int bar, u64 offset, u64 mask, u64 val,
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