[rtems commit] libchip/network/if_fxp.c: do not use rtems_interrupt_disable.

[Pavel Pisa]

Module:    rtems
Branch:    master
Commit:    dfcec5595f0d2510fb950dec50fc4695da00fb59
Changeset: http://git.rtems.org/rtems/commit/?id=dfcec5595f0d2510fb950dec50fc4695da00fb59

Author:    Pavel Pisa <pisa at cmp.felk.cvut.cz>
Date:      Wed Oct 12 10:15:29 2016 +0200

libchip/network/if_fxp.c: do not use rtems_interrupt_disable.

The single write to memory or ioport output are mostly
atomic operations already. The proper memory synchronization barrier
should be used around them to guarantee ordering (sync or eieio
on PowerPC for example) but because I have not found settable
portable primitive only compiler barrier is used.
It should be enough on x86 because the externally visible order
should be/is guaranteed to be preserved on x86 architecture.

---

 c/src/libchip/network/if_fxp.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/c/src/libchip/network/if_fxp.c b/c/src/libchip/network/if_fxp.c
index 4d9d983..c2ca419 100644
--- a/c/src/libchip/network/if_fxp.c
+++ b/c/src/libchip/network/if_fxp.c
@@ -1130,7 +1130,6 @@ fxp_start(struct ifnet *ifp)
 {
 	struct fxp_softc *sc = ifp->if_softc;
 	struct fxp_cb_tx *txp;
-	rtems_interrupt_level level;
 
 	DBGLVL_PRINTK(3,"fxp_start called\n");
 
@@ -1279,10 +1278,10 @@ tbdinit:
 	/*
 	 * reenable interrupts
 	 */
-	rtems_interrupt_disable (level);
+	RTEMS_COMPILER_MEMORY_BARRIER();
 	CSR_WRITE_1(sc, FXP_CSR_SCB_INTRCNTL,0);
 	bsp_interrupt_vector_enable(sc->irq_num);
-	rtems_interrupt_enable (level);
+	RTEMS_COMPILER_MEMORY_BARRIER();
 }
 
 /*
@@ -1311,7 +1310,6 @@ static void fxp_daemon(void *xsc)
 	struct ifnet *ifp = &sc->sc_if;
 	u_int8_t statack;
 	rtems_event_set events;
-	rtems_interrupt_level level;
 
 #ifdef NOTUSED
 	if (sc->suspended) {
@@ -1458,10 +1456,9 @@ rcvloop:
 	  /*
 	   * reenable interrupts
 	   */
-	  rtems_interrupt_disable (level);
+	  RTEMS_COMPILER_MEMORY_BARRIER();
 	  CSR_WRITE_1(sc, FXP_CSR_SCB_INTRCNTL,0);
-	  bsp_interrupt_vector_enable(sc->irq_num);
-	  rtems_interrupt_enable (level);
+	  RTEMS_COMPILER_MEMORY_BARRIER();
 	}
 }