[PATCH v3 13/14] dp8393x: Don't reset Silicon Revision register

[Finn Thain]

The jazzsonic driver in Linux uses the Silicon Revision register value
to probe the chip. The driver fails unless the SR register contains 4.
Unfortunately, reading this register in QEMU usually returns 0 because
the s->regs[] array gets wiped after a software reset.

Fixes: bd8f1ebce4 ("net/dp8393x: fix hardware reset")
Signed-off-by: Finn Thain <address@hidden>
---
 hw/net/dp8393x.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/hw/net/dp8393x.c b/hw/net/dp8393x.c
index 1b73a8703b..71af0fad51 100644
--- a/hw/net/dp8393x.c
+++ b/hw/net/dp8393x.c
@@ -591,6 +591,10 @@ static uint64_t dp8393x_read(void *opaque, hwaddr addr, 
unsigned int size)
                 val |= s->cam[s->regs[SONIC_CEP] & 0xf][2* (SONIC_CAP0 - reg)];
             }
             break;
+        /* Read-only */
+        case SONIC_SR:
+            val = 4; /* only revision recognized by Linux/mips */
+            break;
         /* All other registers have no special contrainst */
         default:
             val = s->regs[reg];
@@ -971,7 +975,6 @@ static void dp8393x_realize(DeviceState *dev, Error **errp)
     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
 
     s->watchdog = timer_new_ns(QEMU_CLOCK_VIRTUAL, dp8393x_watchdog, s);
-    s->regs[SONIC_SR] = 0x0004; /* only revision recognized by Linux */
 
     memory_region_init_ram(&s->prom, OBJECT(dev),
                            "dp8393x-prom", SONIC_PROM_SIZE, &local_err);
-- 
2.24.1