hw/net/npcm_gmac.c: Drop 'buf' local variable

We use the local variable 'buf' only when we call dma_memory_read(),
and it is always set to &tx_send_buffer[prev_buf_size] immediately
before both of those calls.  So remove the variable and pass
tx_send_buffer + prev_buf_size to dma_memory_read().

This fixes in passing a place where we set buf = tx_send_buffer
but never used that value because we always updated buf to
something else later before using it.

Coverity: CID 1534027
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Jason Wang <jasowang@redhat.com>

1 files changed, 4 insertions, 8 deletions

diff --git a/hw/net/npcm_gmac.c b/hw/net/npcm_gmac.c
index 0c17ae9..5e32cd3 100644
--- a/hw/net/npcm_gmac.c
+++ b/hw/net/npcm_gmac.c
@@ -516,7 +516,6 @@ static void gmac_try_send_next_packet(NPCMGMACState *gmac)
     uint32_t desc_addr;
     struct NPCMGMACTxDesc tx_desc;
     uint32_t tx_buf_addr, tx_buf_len;
-    uint8_t *buf = tx_send_buffer;
     uint32_t prev_buf_size = 0;
     int csum = 0;
 
@@ -567,16 +566,15 @@ static void gmac_try_send_next_packet(NPCMGMACState *gmac)
         tx_buf_addr = tx_desc.tdes2;
         gmac->regs[R_NPCM_DMA_CUR_TX_BUF_ADDR] = tx_buf_addr;
         tx_buf_len = TX_DESC_TDES1_BFFR1_SZ_MASK(tx_desc.tdes1);
-        buf = &tx_send_buffer[prev_buf_size];
 
         if ((prev_buf_size + tx_buf_len) > tx_buffer_size) {
             tx_buffer_size = prev_buf_size + tx_buf_len;
             tx_send_buffer = g_realloc(tx_send_buffer, tx_buffer_size);
-            buf = &tx_send_buffer[prev_buf_size];
         }
 
         /* step 5 */
-        if (dma_memory_read(&address_space_memory, tx_buf_addr, buf,
+        if (dma_memory_read(&address_space_memory, tx_buf_addr,
+                            tx_send_buffer + prev_buf_size,
                             tx_buf_len, MEMTXATTRS_UNSPECIFIED)) {
             qemu_log_mask(LOG_GUEST_ERROR, "%s: Failed to read packet @ 0x%x\n",
                         __func__, tx_buf_addr);
@@ -589,15 +587,14 @@ static void gmac_try_send_next_packet(NPCMGMACState *gmac)
             tx_buf_addr = tx_desc.tdes3;
             gmac->regs[R_NPCM_DMA_CUR_TX_BUF_ADDR] = tx_buf_addr;
             tx_buf_len = TX_DESC_TDES1_BFFR2_SZ_MASK(tx_desc.tdes1);
-            buf = &tx_send_buffer[prev_buf_size];
 
             if ((prev_buf_size + tx_buf_len) > tx_buffer_size) {
                 tx_buffer_size = prev_buf_size + tx_buf_len;
                 tx_send_buffer = g_realloc(tx_send_buffer, tx_buffer_size);
-                buf = &tx_send_buffer[prev_buf_size];
             }
 
-            if (dma_memory_read(&address_space_memory, tx_buf_addr, buf,
+            if (dma_memory_read(&address_space_memory, tx_buf_addr,
+                                tx_send_buffer + prev_buf_size,
                                 tx_buf_len, MEMTXATTRS_UNSPECIFIED)) {
                 qemu_log_mask(LOG_GUEST_ERROR,
                               "%s: Failed to read packet @ 0x%x\n",
@@ -615,7 +612,6 @@ static void gmac_try_send_next_packet(NPCMGMACState *gmac)
             net_checksum_calculate(tx_send_buffer, length, csum);
             qemu_send_packet(qemu_get_queue(gmac->nic), tx_send_buffer, length);
             trace_npcm_gmac_packet_sent(DEVICE(gmac)->canonical_path, length);
-            buf = tx_send_buffer;
             prev_buf_size = 0;
         }