[PATCH net-next 08/15] nfp: don't ignore return value of wait_event_interruptible

[Jakub Kicinski]

When signal interrupts waiting for an area to become available
we assume success.  Pay attention to the return code.  Unpack
the code a little bit to make it more readable.

Signed-off-by: Jakub Kicinski <jakub.kicin...@netronome.com>
---
 .../ethernet/netronome/nfp/nfpcore/nfp_cppcore.c   | 56 +++++++++++++++-------
 1 file changed, 38 insertions(+), 18 deletions(-)

diff --git a/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_cppcore.c 
b/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_cppcore.c
index 5189fedb0f4f..2e4796b52b84 100644
--- a/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_cppcore.c
+++ b/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_cppcore.c
@@ -411,9 +411,43 @@ nfp_cpp_area_alloc(struct nfp_cpp *cpp, u32 dest,
  */
 void nfp_cpp_area_free(struct nfp_cpp_area *area)
 {
+       if (atomic_read(&area->refcount))
+               nfp_warn(area->cpp, "Warning: freeing busy area\n");
        nfp_cpp_area_put(area);
 }
 
+static bool nfp_cpp_area_acquire_try(struct nfp_cpp_area *area, int *status)
+{
+       *status = area->cpp->op->area_acquire(area);
+
+       return *status != -EAGAIN;
+}
+
+static int __nfp_cpp_area_acquire(struct nfp_cpp_area *area)
+{
+       int err, status;
+
+       if (atomic_inc_return(&area->refcount) > 1)
+               return 0;
+
+       if (!area->cpp->op->area_acquire)
+               return 0;
+
+       err = wait_event_interruptible(area->cpp->waitq,
+                                      nfp_cpp_area_acquire_try(area, &status));
+       if (!err)
+               err = status;
+       if (err) {
+               nfp_warn(area->cpp, "Warning: area wait failed: %d\n", err);
+               atomic_dec(&area->refcount);
+               return err;
+       }
+
+       nfp_cpp_area_get(area);
+
+       return 0;
+}
+
 /**
  * nfp_cpp_area_acquire() - lock down a CPP area for access
  * @area:      CPP area handle
@@ -425,27 +459,13 @@ void nfp_cpp_area_free(struct nfp_cpp_area *area)
  */
 int nfp_cpp_area_acquire(struct nfp_cpp_area *area)
 {
-       mutex_lock(&area->mutex);
-       if (atomic_inc_return(&area->refcount) == 1) {
-               int (*a_a)(struct nfp_cpp_area *);
-
-               a_a = area->cpp->op->area_acquire;
-               if (a_a) {
-                       int err;
+       int ret;
 
-                       wait_event_interruptible(area->cpp->waitq,
-                                                (err = a_a(area)) != -EAGAIN);
-                       if (err < 0) {
-                               atomic_dec(&area->refcount);
-                               mutex_unlock(&area->mutex);
-                               return err;
-                       }
-               }
-       }
+       mutex_lock(&area->mutex);
+       ret = __nfp_cpp_area_acquire(area);
        mutex_unlock(&area->mutex);
 
-       nfp_cpp_area_get(area);
-       return 0;
+       return ret;
 }
 
 /**
-- 
2.11.0