arm: mvebu: turris_omnia: Switch DDR speed to 1333H when reset 9 is selected
Users experiencing random kernel crashes due to new versions of
Marvell's DDR training algorithm can solve the issue by setting DDR
speed to 1333H.
But if kernel crashes, it has to be done in U-Boot, which is impossible
without UART connection.
In order to make it easier for users, use the rescue button mechanism:
when rescue mode 9 is selected (that is when 10 LEDs are ON), U-Boot
will train DDR in 1333H mode and also update EEPROM so that subsequent
boot will use this mode.
User has to use the `eeprom` command in U-Boot or `omnia-eeprom` command
in OS to switch back to 1600K mode.
Signed-off-by: Marek Behún <kabel@kernel.org>
Reviewed-by: Stefan Roese <sr@denx.de>
diff --git a/board/CZ.NIC/turris_omnia/turris_omnia.c b/board/CZ.NIC/turris_omnia/turris_omnia.c
index 46f20f0..eb88ee7 100644
--- a/board/CZ.NIC/turris_omnia/turris_omnia.c
+++ b/board/CZ.NIC/turris_omnia/turris_omnia.c
@@ -47,6 +47,9 @@
#define OMNIA_I2C_EEPROM_CHIP_LEN 2
#define OMNIA_I2C_EEPROM_MAGIC 0x0341a034
+#define OMNIA_RESET_TO_LOWER_DDR_SPEED 9
+#define OMNIA_LOWER_DDR_SPEED "1333H"
+
#define A385_SYS_RSTOUT_MASK MVEBU_REGISTER(0x18260)
#define A385_SYS_RSTOUT_MASK_WD BIT(10)
@@ -206,6 +209,20 @@
return ~bitrev32(crc);
}
+static int omnia_mcu_get_reset(void)
+{
+ u8 reset_status;
+ int ret;
+
+ ret = omnia_mcu_read(CMD_GET_RESET, &reset_status, 1);
+ if (ret) {
+ printf("omnia_mcu_read failed: %i, reset status unknown!\n", ret);
+ return ret;
+ }
+
+ return reset_status;
+}
+
/* Can only be called after relocation, since it needs cleared BSS */
static int omnia_mcu_board_info(char *serial, u8 *mac, char *version)
{
@@ -463,14 +480,17 @@
return true;
}
+static struct udevice *omnia_get_eeprom(void)
+{
+ return omnia_get_i2c_chip("EEPROM", OMNIA_I2C_EEPROM_CHIP_ADDR,
+ OMNIA_I2C_EEPROM_CHIP_LEN);
+}
+
static bool omnia_read_eeprom(struct omnia_eeprom *oep)
{
- struct udevice *eeprom;
+ struct udevice *eeprom = omnia_get_eeprom();
int ret;
- eeprom = omnia_get_i2c_chip("EEPROM", OMNIA_I2C_EEPROM_CHIP_ADDR,
- OMNIA_I2C_EEPROM_CHIP_LEN);
-
if (!eeprom)
return false;
@@ -502,6 +522,35 @@
return true;
}
+static void omnia_eeprom_set_lower_ddr_speed(void)
+{
+ struct udevice *eeprom = omnia_get_eeprom();
+ struct omnia_eeprom oep;
+ int ret;
+
+ if (!eeprom || !omnia_read_eeprom(&oep))
+ return;
+
+ puts("Setting DDR speed to " OMNIA_LOWER_DDR_SPEED " in EEPROM as requested by reset button... ");
+
+ /* check if already set */
+ if (!strncmp(oep.ddr_speed, OMNIA_LOWER_DDR_SPEED, sizeof(oep.ddr_speed)) &&
+ (oep.old_ddr_training == 0 || oep.old_ddr_training == 0xff)) {
+ puts("was already set\n");
+ return;
+ }
+
+ strncpy(oep.ddr_speed, OMNIA_LOWER_DDR_SPEED, sizeof(oep.ddr_speed));
+ oep.old_ddr_training = 0xff;
+ oep.crc2 = crc32(0, (const void *)&oep, offsetof(struct omnia_eeprom, crc2));
+
+ ret = i2c_eeprom_write(eeprom, 0, (const void *)&oep, sizeof(oep));
+ if (ret)
+ printf("cannot write EEPROM: %d\n", ret);
+ else
+ puts("done\n");
+}
+
int omnia_get_ram_size_gb(void)
{
static int ram_size;
@@ -531,6 +580,13 @@
{
struct omnia_eeprom oep;
+ /*
+ * If lower DDR speed is requested by reset button, we can't use old DDR
+ * training algorithm.
+ */
+ if (omnia_mcu_get_reset() == OMNIA_RESET_TO_LOWER_DDR_SPEED)
+ return false;
+
if (!omnia_read_eeprom(&oep))
return false;
@@ -711,13 +767,19 @@
const struct omnia_ddr_speed *setting;
const char *speed;
static bool done;
+ int reset_status;
if (done)
return;
done = true;
- speed = omnia_get_ddr_speed();
+ reset_status = omnia_mcu_get_reset();
+ if (reset_status == OMNIA_RESET_TO_LOWER_DDR_SPEED)
+ speed = OMNIA_LOWER_DDR_SPEED;
+ else
+ speed = omnia_get_ddr_speed();
+
if (!speed)
return;
@@ -734,7 +796,10 @@
if (params->speed_bin_index == setting->speed_bin)
return;
- printf("Fixing up DDR3 speed (EEPROM defines %s)\n", speed);
+ if (reset_status == OMNIA_RESET_TO_LOWER_DDR_SPEED)
+ printf("Fixing up DDR3 speed to %s as requested by reset button\n", speed);
+ else
+ printf("Fixing up DDR3 speed (EEPROM defines %s)\n", speed);
params->speed_bin_index = setting->speed_bin;
params->memory_freq = setting->freq;
@@ -771,8 +836,7 @@
static void handle_reset_button(void)
{
const char * const vars[1] = { "bootcmd_rescue", };
- int ret;
- u8 reset_status;
+ int reset_status;
/*
* Ensure that bootcmd_rescue has always stock value, so that running
@@ -781,12 +845,12 @@
*/
env_set_default_vars(1, (char * const *)vars, 0);
- ret = omnia_mcu_read(CMD_GET_RESET, &reset_status, 1);
- if (ret) {
- printf("omnia_mcu_read failed: %i, reset status unknown!\n",
- ret);
+ reset_status = omnia_mcu_get_reset();
+ if (reset_status < 0)
return;
- }
+
+ if (reset_status == OMNIA_RESET_TO_LOWER_DDR_SPEED)
+ return omnia_eeprom_set_lower_ddr_speed();
env_set_ulong("omnia_reset", reset_status);