[lkml]   [2019]   [Oct]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Patch in this message
Subject[PATCHv3] ARM: drivers/amba: release and cleanup the resource to allow for deferred probe
With commit "79bdcb202a35 ARM: 8906/1: drivers/amba: add reset control to
amba bus probe", the amba bus driver needs to be deferred probe because the
reset driver is probed later. However with a deferred probe, the call to
request_resource() in the driver returns -EBUSY. The reason is the driver
has not released the resource from the previous probe attempt.

This patch fixes how we handle the condition of EPROBE_DEFER that is returned
from getting the reset controls. For this condition, the patch will jump
to defer_probe, which will iounmap, dev_pm_domain_detach, and release the

Fixes: 79bdcb202a35 ("ARM: 8906/1: drivers/amba: add reset control to
amba bus probe")
Signed-off-by: Dinh Nguyen <>
v3: jump to defer_probe where the driver will unmap and pm_detach the
driver resource for the next probe attempt
v2: release the resource when of_reset_control_array_get_optional_shared()
drivers/amba/bus.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
index f39f075abff9..4a021b1dab3d 100644
--- a/drivers/amba/bus.c
+++ b/drivers/amba/bus.c
@@ -409,9 +409,12 @@ static int amba_device_try_add(struct amba_device *dev, struct resource *parent)
rstc = of_reset_control_array_get_optional_shared(dev->dev.of_node);
if (IS_ERR(rstc)) {
- if (PTR_ERR(rstc) != -EPROBE_DEFER)
+ ret = PTR_ERR(rstc);
+ if (ret == -EPROBE_DEFER)
+ goto defer_probe;
+ else
dev_err(&dev->dev, "Can't get amba reset!\n");
- return PTR_ERR(rstc);
+ return ret;
@@ -448,6 +451,7 @@ static int amba_device_try_add(struct amba_device *dev, struct resource *parent)
ret = -ENODEV;

+ defer_probe:
dev_pm_domain_detach(&dev->dev, true);

 \ /
  Last update: 2019-10-02 16:36    [W:0.071 / U:6.736 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site