xilinx_spips: lqspi: Push more data to tx-fifo

Do 16 words per fifo flush. Increases performance and decreases
debug verbosity. This data depth has no real hardware analogue,
so just go with something that has reasonable performance.

Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Message-id: 5621ee4621941d3639b5cacfdec26bd3148f31d5.1369117359.git.peter.crosthwaite@xilinx.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

diff --git a/hw/ssi/xilinx_spips.c b/hw/ssi/xilinx_spips.c
index 665f471bb15c205e055095374cc0bc08c454788f..e975a876c60ccb7ee0b645e44c2d637c08c9496b 100644 (file)
--- a/hw/ssi/xilinx_spips.c
+++ b/hw/ssi/xilinx_spips.c
@@ -608,11 +608,14 @@ lqspi_read(void *opaque, hwaddr addr, unsigned int size)
 
         DB_PRINT_L(0, "starting QSPI data read\n");
 
-        for (i = 0; i < LQSPI_CACHE_SIZE / 4; ++i) {
-            tx_data_bytes(s, 0, 4);
+        while (cache_entry < LQSPI_CACHE_SIZE / 4) {
+            for (i = 0; i < 16; ++i) {
+                tx_data_bytes(s, 0, 4);
+            }
             xilinx_spips_flush_txfifo(s);
-            rx_data_bytes(s, &q->lqspi_buf[cache_entry], 4);
-            cache_entry++;
+            for (i = 0; i < 16; ++i) {
+                rx_data_bytes(s, &q->lqspi_buf[cache_entry++], 4);
+            }
         }
 
         s->regs[R_LQSPI_STS] &= ~LQSPI_CFG_U_PAGE;