[incubator-nuttx] branch master updated: risc-v/mpfs: IHC: clarify semaphore usage

[pk...@apache.org]

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pkarashchenko pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/incubator-nuttx.git


The following commit(s) were added to refs/heads/master by this push:
     new 0178792a01 risc-v/mpfs: IHC: clarify semaphore usage
0178792a01 is described below

commit 0178792a018c1654a8a6725ca2a3306861afb00d
Author: Eero Nurkkala <ee...@offcode.fi>
AuthorDate: Fri May 13 11:38:29 2022 +0300

    risc-v/mpfs: IHC: clarify semaphore usage
    
    g_mpfs_ack_sig and g_mpfs_rx_sig are better used with
    SEM_INITIALIZER(0) (signalling) rather than with
    SEM_INITIALIZER(1) (mutual exclusion).
    
    Co-authored-by: Petro Karashchenko <pe...@gmail.com>
    Signed-off-by: Eero Nurkkala <ee...@offcode.fi>
---
 arch/risc-v/src/mpfs/mpfs_ihc.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/risc-v/src/mpfs/mpfs_ihc.c b/arch/risc-v/src/mpfs/mpfs_ihc.c
index 4f3c571dd6..f428df6e5d 100755
--- a/arch/risc-v/src/mpfs/mpfs_ihc.c
+++ b/arch/risc-v/src/mpfs/mpfs_ihc.c
@@ -169,8 +169,8 @@ static struct mpfs_rptun_shmem_s    g_shmem;
 static struct rpmsg_device         *g_mpfs_rpmsg_device;
 static struct rpmsg_virtio_device  *g_mpfs_virtio_device;
 
-static sem_t  g_mpfs_ack_lock      = SEM_INITIALIZER(1);
-static sem_t  g_mpfs_rx_sig        = SEM_INITIALIZER(1);
+static sem_t  g_mpfs_ack_sig       = SEM_INITIALIZER(0);
+static sem_t  g_mpfs_rx_sig        = SEM_INITIALIZER(0);
 static struct list_node g_dev_list = LIST_INITIAL_VALUE(g_dev_list);
 
 static uint32_t g_connected_hart_ints;
@@ -335,7 +335,7 @@ static uint32_t mpfs_ihc_context_to_remote_hart_id(ihc_channel_t channel)
  *
  * Description:
  *   This handles the received information and either lets the vq to proceed
- *   via posting g_mpfs_ack_lock, or lets the mpfs_rptun_thread() run as it
+ *   via posting g_mpfs_ack_sig, or lets the mpfs_rptun_thread() run as it
  *   waits for the g_mpfs_rx_sig.  virtqueue_notification() cannot be called
  *   from the interrupt context, thus the thread that will perform it.
  *
@@ -354,7 +354,7 @@ static void mpfs_ihc_rx_handler(uint32_t *message, bool is_ack)
     {
       /* Received the ack */
 
-      nxsem_post(&g_mpfs_ack_lock);
+      nxsem_post(&g_mpfs_ack_sig);
     }
   else
     {
@@ -683,7 +683,7 @@ static int mpfs_ihc_tx_message(ihc_channel_t channel, uint32_t *message)
 
       /* Wait for the ACK to arrive to maintain the logic */
 
-      nxsem_wait_uninterruptible(&g_mpfs_ack_lock);
+      nxsem_wait_uninterruptible(&g_mpfs_ack_sig);
     }
 
   return OK;