net: atlantic: check rpc result and wait for rpc address

Artificial HW reliability tests revealed a possible hangup in
the driver. Normally, when device disappears from bus, all
register reads returns 0xFFFFFFFF.

At remote procedure invocation towards FW there is a logic
where result is compared with -1 in a loop.
That caused an infinite loop if hardware due to some issues
disappears from bus.

Add extra result checks to prevent this.
Signed-off-by: Dmitry Bogdanov <dbogdanov@marvell.com>
Signed-off-by: Igor Russkikh <irusskikh@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/aquantia/atlantic/hw_atl/hw_atl_utils.c

@@ -22,6 +22,7 @@
 #define HW_ATL_MIF_ADDR         0x0208U
 #define HW_ATL_MIF_VAL          0x020CU
 
+#define HW_ATL_MPI_RPC_ADDR     0x0334U
 #define HW_ATL_RPC_CONTROL_ADR  0x0338U
 #define HW_ATL_RPC_STATE_ADR    0x033CU
 
@@ -53,15 +54,14 @@ enum mcp_area {
 };
 
 static int hw_atl_utils_ver_match(u32 ver_expected, u32 ver_actual);
-
 static int hw_atl_utils_mpi_set_state(struct aq_hw_s *self,
 				      enum hal_atl_utils_fw_state_e state);
-
 static u32 hw_atl_utils_get_mpi_mbox_tid(struct aq_hw_s *self);
 static u32 hw_atl_utils_mpi_get_state(struct aq_hw_s *self);
 static u32 hw_atl_utils_mif_cmd_get(struct aq_hw_s *self);
 static u32 hw_atl_utils_mif_addr_get(struct aq_hw_s *self);
 static u32 hw_atl_utils_rpc_state_get(struct aq_hw_s *self);
+static u32 aq_fw1x_rpc_get(struct aq_hw_s *self);
 
 int hw_atl_utils_initfw(struct aq_hw_s *self, const struct aq_fw_ops **fw_ops)
 {
@@ -476,6 +476,10 @@ static int hw_atl_utils_init_ucp(struct aq_hw_s *self,
 					self, self->mbox_addr,
 					self->mbox_addr != 0U,
 					1000U, 10000U);
+	err = readx_poll_timeout_atomic(aq_fw1x_rpc_get, self,
+					self->rpc_addr,
+					self->rpc_addr != 0U,
+					1000U, 100000U);
 
 	return err;
 }
@@ -531,6 +535,12 @@ int hw_atl_utils_fw_rpc_wait(struct aq_hw_s *self,
 						self, fw.val,
 						sw.tid == fw.tid,
 						1000U, 100000U);
+		if (err < 0)
+			goto err_exit;
+
+		err = aq_hw_err_from_flags(self);
+		if (err < 0)
+			goto err_exit;
 
 		if (fw.len == 0xFFFFU) {
 			err = hw_atl_utils_fw_rpc_call(self, sw.len);
@@ -1025,6 +1035,11 @@ static u32 hw_atl_utils_rpc_state_get(struct aq_hw_s *self)
 	return aq_hw_read_reg(self, HW_ATL_RPC_STATE_ADR);
 }
 
+static u32 aq_fw1x_rpc_get(struct aq_hw_s *self)
+{
+	return aq_hw_read_reg(self, HW_ATL_MPI_RPC_ADDR);
+}
+
 const struct aq_fw_ops aq_fw_1x_ops = {
 	.init = hw_atl_utils_mpi_create,
 	.deinit = hw_atl_fw1x_deinit,