bios/sdram: add ERR_DDRPH_BITSLIP constant and some cleanup

diff --git a/litex/soc/software/bios/sdram.c b/litex/soc/software/bios/sdram.c
index cd06491a0de6a60fb91f0eb0b21ef2c1f217d195..59cfa8a92684de5ee0a1f736ce5d1911297f065a 100644 (file)
--- a/litex/soc/software/bios/sdram.c
+++ b/litex/soc/software/bios/sdram.c
@@ -203,6 +203,7 @@ void sdrwr(char *startaddr)
 #else
 #define ERR_DDRPHY_DELAY 32
 #endif
+#define ERR_DDRPHY_BITSLIP 8
 
 #ifdef CSR_DDRPHY_WLEVEL_EN_ADDR
 
@@ -748,14 +749,15 @@ int sdrlevel(void)
                return 0;
 #endif
        /* check for optimal read leveling window */
-       for(i=0; i<8; i++) {
-               if (read_level_scan(1)) {
+       for(i=0; i<ERR_DDRPHY_BITSLIP; i++) {
+               /* scan */
+               if (read_level_scan(1))
                        break;
-               } else {
-                       /* else increment bitslip and re-scan */
-                       for(j=0; j<DFII_PIX_DATA_SIZE/2; j++)
-                               read_bitslip_inc(j);
-               }
+               if (i == ERR_DDRPHY_BITSLIP-1)
+                       return 0;
+               /* increment bitslip */
+               for(j=0; j<DFII_PIX_DATA_SIZE/2; j++)
+                       read_bitslip_inc(j);
        }
        /* show bitslip and scan */
        printf("Read bitslip: %d\n", i);