spi: Merge AMD fix

Work around problems with large transfers.

Author: broonie

drivers/spi/spi-amd.c

@@ -33,6 +33,7 @@
 #define AMD_SPI_RX_COUNT_REG	0x4B
 #define AMD_SPI_STATUS_REG	0x4C
 
+#define AMD_SPI_FIFO_SIZE	70
 #define AMD_SPI_MEM_SIZE	200
 
 /* M_CMD OP codes for SPI */
@@ -270,6 +271,11 @@ static int amd_spi_master_transfer(struct spi_master *master,
 	return 0;
 }
 
+static size_t amd_spi_max_transfer_size(struct spi_device *spi)
+{
+	return AMD_SPI_FIFO_SIZE;
+}
+
 static int amd_spi_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -302,6 +308,8 @@ static int amd_spi_probe(struct platform_device *pdev)
 	master->flags = SPI_MASTER_HALF_DUPLEX;
 	master->setup = amd_spi_master_setup;
 	master->transfer_one_message = amd_spi_master_transfer;
+	master->max_transfer_size = amd_spi_max_transfer_size;
+	master->max_message_size = amd_spi_max_transfer_size;
 
 	/* Register the controller with SPI framework */
 	err = devm_spi_register_master(dev, master);