From: Shiva sagar Myana <Shivasagar.Myana@amd.com>

Ensure that the FIFO is checked for emptiness before popping data
from it.  Previously, the code directly popped the data from the FIFO
without checking, which could cause an assertion failure:

../util/fifo8.c:67: fifo8_pop: Assertion `fifo->num > 0' failed.

Signed-off-by: Shiva sagar Myana <Shivasagar.Myana@amd.com>
Message-id: 20240924112035.1320865-1-Shivasagar.Myana@amd.com
Reviewed-by: Francisco Iglesias <francisco.iglesias@amd.com>
[PMM: tweaked commit message]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 hw/ssi/xilinx_spips.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/hw/ssi/xilinx_spips.c b/hw/ssi/xilinx_spips.c
index 1595a887a1d..aeb462c3cec 100644
--- a/hw/ssi/xilinx_spips.c
+++ b/hw/ssi/xilinx_spips.c
@@ -620,7 +620,9 @@ static void xilinx_spips_flush_txfifo(XilinxSPIPS *s)
         } else if (s->snoop_state == SNOOP_STRIPING ||
                    s->snoop_state == SNOOP_NONE) {
             for (i = 0; i < num_effective_busses(s); ++i) {
-                tx_rx[i] = fifo8_pop(&s->tx_fifo);
+                if (!fifo8_is_empty(&s->tx_fifo)) {
+                    tx_rx[i] = fifo8_pop(&s->tx_fifo);
+                }
             }
             stripe8(tx_rx, num_effective_busses(s), false);
         } else if (s->snoop_state >= SNOOP_ADDR) {
-- 
2.34.1