[PULL 06/11] hw/net/imx_fec: write TGSR and TCSR3 in imx_enet_write()

[Peter Maydell <peter.maydell@linaro.org>]

From: Chen Qun <kuhn.chenqun@huawei.com>

The current code causes clang static code analyzer generate warning:
hw/net/imx_fec.c:858:9: warning: Value stored to 'value' is never read
        value = value & 0x0000000f;
        ^       ~~~~~~~~~~~~~~~~~~
hw/net/imx_fec.c:864:9: warning: Value stored to 'value' is never read
        value = value & 0x000000fd;
        ^       ~~~~~~~~~~~~~~~~~~

According to the definition of the function, the two “value” assignments
 should be written to registers.

Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Chen Qun <kuhn.chenqun@huawei.com>
Message-id: 20200313123242.13236-1-kuhn.chenqun@huawei.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 hw/net/imx_fec.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/hw/net/imx_fec.c b/hw/net/imx_fec.c
index 6a124a154a8..5c145a8197e 100644
--- a/hw/net/imx_fec.c
+++ b/hw/net/imx_fec.c
@@ -855,13 +855,15 @@ static void imx_enet_write(IMXFECState *s, uint32_t index, uint32_t value)
         break;
     case ENET_TGSR:
         /* implement clear timer flag */
-        value = value & 0x0000000f;
+        s->regs[index] &= ~(value & 0x0000000f); /* all bits W1C */
         break;
     case ENET_TCSR0:
     case ENET_TCSR1:
     case ENET_TCSR2:
     case ENET_TCSR3:
-        value = value & 0x000000fd;
+        s->regs[index] &= ~(value & 0x00000080); /* W1C bits */
+        s->regs[index] &= ~0x0000007d; /* writable fields */
+        s->regs[index] |= (value & 0x0000007d);
         break;
     case ENET_TCCR0:
     case ENET_TCCR1:
-- 
2.20.1