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authorNico Huber <nico.huber@secunet.com>2013-05-14 12:15:05 +0200
committerStefan Reinauer <stefan.reinauer@coreboot.org>2013-05-22 18:05:34 +0200
commit12276acfd7d4847a79ce0c6aade8f33b2836f4df (patch)
tree54b84fdb9044597e5cb1bbd9f931851192f446de /src/northbridge/intel/gm45
parent08bee23f7eb31cce4746c51cfde3a7017e0e8b8e (diff)
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intel/gm45: Handle overflows during DDR3 write training
We halted the machine on any overflow during the write training. However, overflows during the search for a good to bad edge are non-fatal, and should be ignored. Change-Id: I45ccbabc214e208974039246d806b0d2ca2fdc03 Signed-off-by: Nico Huber <nico.huber@secunet.com> Reviewed-on: http://review.coreboot.org/3256 Tested-by: build bot (Jenkins) Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Diffstat (limited to 'src/northbridge/intel/gm45')
-rw-r--r--src/northbridge/intel/gm45/raminit_read_write_training.c91
1 files changed, 63 insertions, 28 deletions
diff --git a/src/northbridge/intel/gm45/raminit_read_write_training.c b/src/northbridge/intel/gm45/raminit_read_write_training.c
index 72c83a7275e9..65e16a3b5f2f 100644
--- a/src/northbridge/intel/gm45/raminit_read_write_training.c
+++ b/src/northbridge/intel/gm45/raminit_read_write_training.c
@@ -342,7 +342,7 @@ typedef struct {
const int t_bound;
int p;
} write_timing_t;
-static void normalize_write_timing(write_timing_t *const timing)
+static int normalize_write_timing(write_timing_t *const timing)
{
while (timing->p >= WRITE_TIMING_P_BOUND) {
timing->t++;
@@ -360,16 +360,31 @@ static void normalize_write_timing(write_timing_t *const timing)
timing->f--;
timing->t += timing->t_bound;
}
- if ((timing->f < 0) || (timing->f >= WRITE_TIMING_F_BOUND))
- die("Timing under-/overflow during write training.\n");
+ if (timing->f < 0) {
+ printk(BIOS_WARNING,
+ "Timing underflow during write training.\n");
+ timing->f = 0;
+ timing->t = 0;
+ timing->p = 0;
+ return -1;
+ } else if (timing->f >= WRITE_TIMING_F_BOUND) {
+ printk(BIOS_WARNING,
+ "Timing overflow during write training.\n");
+ timing->f = WRITE_TIMING_F_BOUND - 1;
+ timing->t = timing->t_bound - 1;
+ timing->p = WRITE_TIMING_P_BOUND - 1;
+ return -1;
+ }
+ return 0;
}
-static void program_write_timing(const int ch, const int group,
- write_timing_t *const timing, int memclk1067)
+static int program_write_timing(const int ch, const int group,
+ write_timing_t *const timing, int memclk1067)
{
/* MEM_CLOCK_1067MT? X lower/upper */
const u32 d_bounds[2][2] = { { 1, 6 }, { 2, 9 } };
- normalize_write_timing(timing);
+ if (normalize_write_timing(timing) < 0)
+ return -1;
const int f = timing->f;
const int t = timing->t;
@@ -385,6 +400,8 @@ static void program_write_timing(const int ch, const int group,
reg &= ~CxWRTy_D_MASK;
reg |= CxWRTy_T(t) | CxWRTy_P(p) | CxWRTy_F(f) | d;
MCHBAR32(CxWRTy_MCHBAR(ch, group)) = reg;
+
+ return 0;
}
/* Returns 1 on success, 0 on failure. */
static int write_training_test(const address_bunch_t *const addresses,
@@ -426,45 +443,61 @@ _bad_timing_out:
return ret;
}
-static void write_training_find_lower(const int ch, const int group,
- const address_bunch_t *const addresses,
- const u32 masks[][2], const int memclk1067,
- write_timing_t *const lower)
+static int write_training_find_lower(const int ch, const int group,
+ const address_bunch_t *const addresses,
+ const u32 masks[][2], const int memclk1067,
+ write_timing_t *const lower)
{
program_write_timing(ch, group, lower, memclk1067);
/* Coarse search for good t. */
while (!write_training_test(addresses, masks[group])) {
++lower->t;
- program_write_timing(ch, group, lower, memclk1067);
+ if (program_write_timing(ch, group, lower, memclk1067) < 0)
+ return -1;
}
- /* Fine search for good p. */
+ /* Step back, then fine search for good p. */
+ if ((lower->f <= 0) && (lower->t <= 0))
+ /* Can't step back, zero is good. */
+ return 0;
+
--lower->t;
program_write_timing(ch, group, lower, memclk1067);
while (!write_training_test(addresses, masks[group])) {
++lower->p;
- program_write_timing(ch, group, lower, memclk1067);
+ if (program_write_timing(ch, group, lower, memclk1067) < 0)
+ return -1;
}
+
+ return 0;
}
-static void write_training_find_upper(const int ch, const int group,
- const address_bunch_t *const addresses,
- const u32 masks[][2], const int memclk1067,
- write_timing_t *const upper)
+static int write_training_find_upper(const int ch, const int group,
+ const address_bunch_t *const addresses,
+ const u32 masks[][2], const int memclk1067,
+ write_timing_t *const upper)
{
- program_write_timing(ch, group, upper, memclk1067);
- if (!write_training_test(addresses, masks[group]))
- die("Write training failed; limits too narrow.\n");
- /* Coarse search for good t. */
+ if (program_write_timing(ch, group, upper, memclk1067) < 0)
+ return -1;
+ if (!write_training_test(addresses, masks[group])) {
+ printk(BIOS_WARNING,
+ "Write training failure; limits too narrow.\n");
+ return -1;
+ }
+ /* Coarse search for bad t. */
while (write_training_test(addresses, masks[group])) {
++upper->t;
- program_write_timing(ch, group, upper, memclk1067);
+ if (program_write_timing(ch, group, upper, memclk1067) < 0)
+ return -1;
}
- /* Fine search for good p. */
+ /* Fine search for bad p. */
--upper->t;
program_write_timing(ch, group, upper, memclk1067);
while (write_training_test(addresses, masks[group])) {
++upper->p;
- program_write_timing(ch, group, upper, memclk1067);
+ if (program_write_timing(ch, group, upper, memclk1067) < 0)
+ return -1;
}
+
+ return 0;
}
static void write_training_per_group(const int ch, const int group,
const address_bunch_t *const addresses,
@@ -482,8 +515,9 @@ static void write_training_per_group(const int ch, const int group,
lower.p = (reg >> 8) & 0x7;
lower.f = ((reg >> 2) & 0x3) - 1;
- write_training_find_lower(ch, group, addresses,
- masks, memclk1067, &lower);
+ if (write_training_find_lower(ch, group, addresses,
+ masks, memclk1067, &lower) < 0)
+ die("Write training failure: lower bound.\n");
/*** Search upper bound. ***/
@@ -492,8 +526,9 @@ static void write_training_per_group(const int ch, const int group,
upper.p = lower.p;
upper.f = lower.f;
- write_training_find_upper(ch, group, addresses,
- masks, memclk1067, &upper);
+ if (write_training_find_upper(ch, group, addresses,
+ masks, memclk1067, &upper) < 0)
+ printk(BIOS_WARNING, "Write training failure: upper bound.\n");
/*** Calculate and program mean value. ***/