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>
This commit is contained in:
Nico Huber 2013-05-14 12:15:05 +02:00 committed by Stefan Reinauer
parent 08bee23f7e
commit 12276acfd7
1 changed files with 63 additions and 28 deletions

View File

@ -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. ***/