can: mcp251xfd: mcp25xxfd_ring_alloc(): add define instead open coding the...

can: mcp251xfd: mcp25xxfd_ring_alloc(): add define instead open coding the maximum number of RX objects

This patch add a define for the maximum number of RX objects instead of open
coding it.

Link: https://lore.kernel.org/r/20201126132144.351154-2-mkl@pengutronix.deTested-by: NThomas Kopp <thomas.kopp@microchip.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c

@@ -416,7 +416,8 @@ static int mcp251xfd_ring_alloc(struct mcp251xfd_priv *priv)
 		int rx_obj_num;
 
 		rx_obj_num = ram_free / rx_obj_size;
-		rx_obj_num = min(1 << (fls(rx_obj_num) - 1), 32);
+		rx_obj_num = min(1 << (fls(rx_obj_num) - 1),
+				 MCP251XFD_RX_OBJ_NUM_MAX);
 
 		rx_ring = kzalloc(sizeof(*rx_ring) + rx_obj_size * rx_obj_num,
 				  GFP_KERNEL);

drivers/net/can/spi/mcp251xfd/mcp251xfd.h

@@ -368,6 +368,7 @@
  * FIFO setup: tef: 8*12 bytes = 96 bytes, tx: 8*16 bytes = 128 bytes
  * FIFO setup: tef: 4*12 bytes = 48 bytes, tx: 4*72 bytes = 288 bytes
  */
+#define MCP251XFD_RX_OBJ_NUM_MAX 32
 #define MCP251XFD_TX_OBJ_NUM_CAN 8
 #define MCP251XFD_TX_OBJ_NUM_CANFD 4