diff --git a/src/drivers/net/phantom/phantom.c b/src/drivers/net/phantom/phantom.c
index 509a7096..8f0453cc 100644
--- a/src/drivers/net/phantom/phantom.c
+++ b/src/drivers/net/phantom/phantom.c
@@ -1711,7 +1711,8 @@ static int phantom_init_cmdpeg ( struct phantom_nic *phantom ) {
 			 UNM_NIC_REG_DUMMY_BUF );
 
 	/* Tell the hardware that tuning is complete */
-	phantom_writel ( phantom, 1, UNM_ROMUSB_GLB_PEGTUNE_DONE );
+	phantom_writel ( phantom, UNM_ROMUSB_GLB_PEGTUNE_DONE_MAGIC,
+			 UNM_ROMUSB_GLB_PEGTUNE_DONE );
 
 	/* Wait for command PEG to finish initialising */
 	DBGC ( phantom, "Phantom %p initialising command PEG (will take up to "
@@ -1859,6 +1860,17 @@ static int phantom_probe ( struct pci_device *pci,
 		phantom_port->port = i;
 	}
 
+	/* BUG5945 - need to hack PCI config space on P3 B1 silicon.
+	 * B2 will have this fixed; remove this hack when B1 is no
+	 * longer in use.
+	 */
+	{
+		uint32_t temp;
+		pci_read_config_dword ( pci, 0xc8, &temp );
+		pci_read_config_dword ( pci, 0xc8, &temp );
+		pci_write_config_dword ( pci, 0xc8, 0xf1000 );
+	}
+
 	/* Allocate dummy DMA buffer and perform initial hardware handshake */
 	phantom->dma_buf = malloc_dma ( sizeof ( *(phantom->dma_buf) ),
 					UNM_DMA_BUFFER_ALIGN );
diff --git a/src/drivers/net/phantom/phantom.h b/src/drivers/net/phantom/phantom.h
index 3c759989..110c1226 100644
--- a/src/drivers/net/phantom/phantom.h
+++ b/src/drivers/net/phantom/phantom.h
@@ -139,6 +139,7 @@ enum unm_reg_blocks {
 #define UNM_ROMUSB_GLB_SW_RESET		( UNM_ROMUSB_GLB + 0x00008 )
 #define UNM_ROMUSB_GLB_SW_RESET_MAGIC		0x0080000fUL
 #define UNM_ROMUSB_GLB_PEGTUNE_DONE	( UNM_ROMUSB_GLB + 0x0005c )
+#define UNM_ROMUSB_GLB_PEGTUNE_DONE_MAGIC	0x31
 
 #define UNM_ROMUSB_ROM			( UNM_CRB_ROMUSB + 0x10000 )
 #define UNM_ROMUSB_ROM_INSTR_OPCODE	( UNM_ROMUSB_ROM + 0x00004 )