The loopback driver allows the user to set a minimum delay of up to one
second to be inserted between test iterations (i.e. request
submissions). The delay is currently specified in microseconds and is
implemented using udelay.
Busy looping for long periods is not just anti-social; udelay must not
be used for delays longer than a few milliseconds due to the risk of
integer overflow.
Replace the broken udelay with a usleep_range with a 100 us range for
short delays (< 20 ms) and otherwise revert to using msleep.
Fixes: b36f04fa9417 ("greybus: loopback: Convert thread delay to
microseconds")
Signed-off-by: Johan Hovold <johan(a)kernel.org>
---
drivers/staging/greybus/loopback.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/staging/greybus/loopback.c b/drivers/staging/greybus/loopback.c
index 6c2a41c638c3..a8329daf1e57 100644
--- a/drivers/staging/greybus/loopback.c
+++ b/drivers/staging/greybus/loopback.c
@@ -1061,8 +1061,13 @@ static int gb_loopback_fn(void *data)
gb_loopback_calculate_stats(gb, !!error);
}
gb->send_count++;
- if (us_wait)
- udelay(us_wait);
+
+ if (us_wait) {
+ if (us_wait < 20000)
+ usleep_range(us_wait, us_wait + 100);
+ else
+ msleep(us_wait / 1000);
+ }
}
gb_pm_runtime_put_autosuspend(bundle);
--
2.10.2
This driver does not have a low-latency mode and should not report
anything else.
Also drop the skip-test flag which isn't used either.
Signed-off-by: Johan Hovold <johan(a)kernel.org>
---
drivers/staging/greybus/uart.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/drivers/staging/greybus/uart.c b/drivers/staging/greybus/uart.c
index 6d39f4a04754..248ad6661a02 100644
--- a/drivers/staging/greybus/uart.c
+++ b/drivers/staging/greybus/uart.c
@@ -624,7 +624,6 @@ static int get_serial_info(struct gb_tty *gb_tty,
struct serial_struct tmp;
memset(&tmp, 0, sizeof(tmp));
- tmp.flags = ASYNC_LOW_LATENCY | ASYNC_SKIP_TEST;
tmp.type = PORT_16550A;
tmp.line = gb_tty->minor;
tmp.xmit_fifo_size = 16;
--
2.10.2
When tearingdown timesync, and not in arche platform, the state platform
callback is not initialized. That will trigger the following NULL
dereferencing.
CallTrace:
? gb_timesync_platform_unlock_bus+0x11/0x20 [greybus]
gb_timesync_teardown+0x85/0xc0 [greybus]
gb_timesync_svc_remove+0xab/0x190 [greybus]
gb_svc_del+0x29/0x110 [greybus]
gb_hd_del+0x14/0x20 [greybus]
ap_disconnect+0x24/0x60 [gb_es2]
usb_unbind_interface+0x7a/0x2c0
__device_release_driver+0x96/0x150
device_release_driver+0x1e/0x30
bus_remove_device+0xe7/0x130
device_del+0x116/0x230
usb_disable_device+0x97/0x1f0
usb_disconnect+0x80/0x260
hub_event+0x5ca/0x10e0
process_one_work+0x126/0x3b0
worker_thread+0x55/0x4c0
? process_one_work+0x3b0/0x3b0
kthread+0xc4/0xe0
? kthread_park+0xb0/0xb0
ret_from_fork+0x22/0x30
So, fix that by adding checks before use the callback.
Fixes: 970dc85bd95d ("greybus: timesync: Add timesync core driver")
Cc: <stable(a)vger.kernel.org> # 4.9.x
Signed-off-by: Rui Miguel Silva <rmfrfs(a)gmail.com>
---
Greg,
This patch does not contain the "commit <sha> upstream" snippet since you
already removed the timesync code from the -next tree, even though it is still
in 4.10-rc. However this will affect the greybus users of 4.9.x. If you
meanwhile pull that remove to rc, this patch is only necessary in stable 4.9.x.
v1->v2:
- add Fixes tag to changelog
Johan Hovold:
- for symmetry with the lock, adjust the unlock_bus function accordantly.
drivers/staging/greybus/timesync_platform.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/staging/greybus/timesync_platform.c b/drivers/staging/greybus/timesync_platform.c
index 113f3d6c4b3a..27f75b17679b 100644
--- a/drivers/staging/greybus/timesync_platform.c
+++ b/drivers/staging/greybus/timesync_platform.c
@@ -45,12 +45,18 @@ u32 gb_timesync_platform_get_clock_rate(void)
int gb_timesync_platform_lock_bus(struct gb_timesync_svc *pdata)
{
+ if (!arche_platform_change_state_cb)
+ return 0;
+
return arche_platform_change_state_cb(ARCHE_PLATFORM_STATE_TIME_SYNC,
pdata);
}
void gb_timesync_platform_unlock_bus(void)
{
+ if (!arche_platform_change_state_cb)
+ return;
+
arche_platform_change_state_cb(ARCHE_PLATFORM_STATE_ACTIVE, NULL);
}
--
2.11.0