diff options
| -rw-r--r-- | drivers/net/can/flexcan.c | 31 |
1 files changed, 23 insertions, 8 deletions
diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c index 5c6903e23c01..52d73115c7fd 100644 --- a/drivers/net/can/flexcan.c +++ b/drivers/net/can/flexcan.c @@ -190,7 +190,7 @@ #define FLEXCAN_QUIRK_DISABLE_RXFG BIT(2) /* Enable EACEN and RRS bit in ctrl2 */ #define FLEXCAN_QUIRK_ENABLE_EACEN_RRS BIT(3) -/* Disable Memory error detection */ +/* Disable non-correctable errors interrupt and freeze mode */ #define FLEXCAN_QUIRK_DISABLE_MECR BIT(4) /* Use timestamp based offloading */ #define FLEXCAN_QUIRK_USE_OFF_TIMESTAMP BIT(5) @@ -1221,28 +1221,43 @@ static int flexcan_chip_start(struct net_device *dev) for (i = 0; i < priv->mb_count; i++) priv->write(0, ®s->rximr[i]); - /* On Vybrid, disable memory error detection interrupts - * and freeze mode. - * This also works around errata e5295 which generates - * false positive memory errors and put the device in - * freeze mode. + /* On Vybrid, disable non-correctable errors interrupt and + * freeze mode. It still can correct the correctable errors + * when HW supports ECC. + * + * This also works around errata e5295 which generates false + * positive memory errors and put the device in freeze mode. */ if (priv->devtype_data->quirks & FLEXCAN_QUIRK_DISABLE_MECR) { /* Follow the protocol as described in "Detection * and Correction of Memory Errors" to write to - * MECR register + * MECR register (step 1 - 5) + * + * 1. By default, CTRL2[ECRWRE] = 0, MECR[ECRWRDIS] = 1 + * 2. set CTRL2[ECRWRE] */ reg_ctrl2 = priv->read(®s->ctrl2); reg_ctrl2 |= FLEXCAN_CTRL2_ECRWRE; priv->write(reg_ctrl2, ®s->ctrl2); + /* 3. clear MECR[ECRWRDIS] */ reg_mecr = priv->read(®s->mecr); reg_mecr &= ~FLEXCAN_MECR_ECRWRDIS; priv->write(reg_mecr, ®s->mecr); - reg_mecr |= FLEXCAN_MECR_ECCDIS; + + /* 4. all writes to MECR must keep MECR[ECRWRDIS] cleared */ reg_mecr &= ~(FLEXCAN_MECR_NCEFAFRZ | FLEXCAN_MECR_HANCEI_MSK | FLEXCAN_MECR_FANCEI_MSK); priv->write(reg_mecr, ®s->mecr); + + /* 5. after configuration done, lock MECR by either + * setting MECR[ECRWRDIS] or clearing CTRL2[ECRWRE] + */ + reg_mecr |= FLEXCAN_MECR_ECRWRDIS; + priv->write(reg_mecr, ®s->mecr); + + reg_ctrl2 &= ~FLEXCAN_CTRL2_ECRWRE; + priv->write(reg_ctrl2, ®s->ctrl2); } err = flexcan_transceiver_enable(priv); |