Solves spinlock-panic in CentOS 4.

zt_transmit() was called in spinlock protected context. However, it may
call back our hook setting code which tries to lock the same spinlock.

As a safeguard, the same logic was applied to zt_receive().

git-svn-id: http://svn.digium.com/svn/zaptel/trunk@1289 5390a7c7-147a-4af0-8ec9-7488f05a26cb

1 files changed, 11 insertions, 1 deletions

diff --git a/xpp/xpp_zap.c b/xpp/xpp_zap.c
index 3e7fc9c..3aad1d4 100644
--- a/xpp/xpp_zap.c
+++ b/xpp/xpp_zap.c
@@ -903,7 +903,13 @@ static void xpp_transmitprep(xpd_t *xpd)
 	} else {
 		w = writechunk = xpd->writechunk + ZT_CHUNKSIZE * CHANNELS_PERXPD /* + 1 */;
 	}
+	spin_unlock_irqrestore(&xpd->lock, flags);
+	/*
+	 * This should be out of spinlocks, as it may call back our hook setting
+	 * methods
+	 */
 	zt_transmit(&xpd->span);
+	spin_lock_irqsave(&xpd->lock, flags);
 
 	for (i = 0; i < channels; i++) {
 		if (xpd->delay_until_dialtone[i] > 0) {
@@ -1011,8 +1017,12 @@ static void xpp_receiveprep(xpd_t *xpd)
 		memcpy(xpd->ec_chunk1[i], chans[i].writechunk, ZT_CHUNKSIZE);
 	}
 #endif
-	zt_receive(&xpd->span);
 	spin_unlock_irqrestore(&xpd->lock, flags);
+	/*
+	 * This should be out of spinlocks, as it may call back our hook setting
+	 * methods
+	 */
+	zt_receive(&xpd->span);
 }
 
 static int xpp_startup(struct zt_span *span)