his patch fixes the CAS map for -.5 and -1 CAS settings. The -.5 setting should only...

Signed-off-by: Marc Jones <marc.jones@amd.com>
Acked-by: Ronald G. Minnich <rminnich@gmail.com>
Acked-by: Jordan Crouse <jordan.crouse@amd.com>
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@2722 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1

diff --git a/src/northbridge/amd/lx/raminit.c b/src/northbridge/amd/lx/raminit.c
index a8555823f6d7af713157ee62f4065d060ac82a82..9981f58cae0802c0f0dd1336519241059c862d41 100644 (file)
--- a/src/northbridge/amd/lx/raminit.c
+++ b/src/northbridge/amd/lx/raminit.c
@@ -151,7 +151,7 @@ static void checkDDRMax(void)
        }
 
        /* I don't think you need this check.
-          if (spd_byte0 < 0xA0 || spd_byte0 < 0xA0){
+          if (spd_byte0 >= 0xA0 || spd_byte1 >= 0xA0){
           print_debug("DIMM overclocked. Check GeodeLink Speed\n");
           POST_CODE(POST_PLL_MEM_FAIL);
           __asm__       __volatile__("hlt\n");
@@ -231,7 +231,7 @@ static void setCAS(void)
 ;*     Destroys: We really use everything !
 ;*****************************************************************************/
        uint16_t glspeed, dimm_speed;
-       uint8_t spd_byte, casmap0, casmap1;
+       uint8_t spd_byte, casmap0, casmap1, casmap_shift;
        msr_t msr;
 
        glspeed = GeodeLinkSpeed();
@@ -246,25 +246,24 @@ static void setCAS(void)
                        dimm_speed = 2 * (10000 / (((spd_byte >> 4) * 10) +
                                                (spd_byte & 0x0F)));
                        if (dimm_speed >= glspeed) {
+                               casmap_shift = 1; /* -.5 is a shift of 1 */
                                /* IF -1 timing is supported, check -1 timing > GeodeLink */
                                spd_byte = spd_read_byte(DIMM0, SPD_SDRAM_CYCLE_TIME_3RD);
                                if (spd_byte != 0) {
                                        /* Turn SPD ns time into MHZ. Check what the asm does to this math. */
                                        dimm_speed = 2 * (10000 / (((spd_byte >> 4) * 10) + (spd_byte & 0x0F)));
-                                       if (dimm_speed <= glspeed) {
-                                               /* set we can use -.5 timing but not -1 */
-                                               spd_byte = 31 - __builtin_clz((uint32_t) casmap0);
-                                               /* just want bits in the lower byte since we have to cast to a 32 */
-                                               casmap0 &= 0xFF << (--spd_byte);
+                                       if (dimm_speed >= glspeed) {
+                                               casmap_shift = 2; /* -1 is a shift of 2 */
                                        }
-                               }       /*MIN_CYCLE_10 !=0 */
+                               }       /* SPD_SDRAM_CYCLE_TIME_3RD (-1) !=0 */
                        } else {
-                               /* Timing_05 < GLspeed, can't use -.5 or -1 timing */
-                               spd_byte = 31 - __builtin_clz((uint32_t) casmap0);
-                               /* just want bits in the lower byte since we have to cast to a 32 */
-                               casmap0 &= 0xFF << (spd_byte);
+                               casmap_shift = 0;
                        }
-               }               /*MIN_CYCLE_05 !=0 */
+               }       /* SPD_SDRAM_CYCLE_TIME_2ND (-.5) !=0 */
+               /* set the casmap based on the shift to limit possible CAS settings */
+               spd_byte = 31 - __builtin_clz((uint32_t) casmap0);
+               /* just want bits in the lower byte since we have to cast to a 32 */
+               casmap0 &= 0xFF << (spd_byte - casmap_shift);
        } else {                /* No DIMM */
                casmap0 = 0;
        }
@@ -278,25 +277,25 @@ static void setCAS(void)
                        /* Turn SPD ns time into MHZ. Check what the asm does to this math. */
                        dimm_speed = 2 * (10000 / (((spd_byte >> 4) * 10) + (spd_byte & 0x0F)));
                        if (dimm_speed >= glspeed) {
+                               casmap_shift = 1; /* -.5 is a shift of 1 */
                                /* IF -1 timing is supported, check -1 timing > GeodeLink */
                                spd_byte = spd_read_byte(DIMM1, SPD_SDRAM_CYCLE_TIME_3RD);
                                if (spd_byte != 0) {
                                        /* Turn SPD ns time into MHZ. Check what the asm does to this math. */
                                        dimm_speed = 2 * (10000 / (((spd_byte >> 4) * 10) + (spd_byte & 0x0F)));
-                                       if (dimm_speed <= glspeed) {
-                                               /* set we can use -.5 timing but not -1 */
-                                               spd_byte = 31 - __builtin_clz((uint32_t) casmap1);
-                                               /* just want bits in the lower byte since we have to cast to a 32 */
-                                               casmap1 &= 0xFF << (--spd_byte);
+                                       if (dimm_speed >= glspeed) {
+                                               casmap_shift = 2; /* -1 is a shift of 2 */
                                        }
-                               }       /*MIN_CYCLE_10 !=0 */
+                                       /* note that the -1 result doesn't need to change the available CAS map */
+                               }       /* SPD_SDRAM_CYCLE_TIME_3RD (-1) !=0 */
                        } else {
-                               /* Timing_05 < GLspeed, can't use -.5 or -1 timing */
-                               spd_byte = 31 - __builtin_clz((uint32_t) casmap1);
-                               /* just want bits in the lower byte since we have to cast to a 32 */
-                               casmap1 &= 0xFF << (spd_byte);
+                               casmap_shift = 0;
                        }
-               }               /*MIN_CYCLE_05 !=0 */
+               }       /* SPD_SDRAM_CYCLE_TIME_2ND (-.5) !=0 */
+               /* set the casmap based on the shift to limit possible CAS settings */
+               spd_byte = 31 - __builtin_clz((uint32_t) casmap1);
+               /* just want bits in the lower byte since we have to cast to a 32 */
+               casmap1 &= 0xFF << (spd_byte - casmap_shift);
        } else {                /* No DIMM */
                casmap1 = 0;
        }