Implement the workaround for erratum 3.3 RGMII timing may be out of spec when transmit delay is enabled for the 6320 family, which says:

When transmit delay is enabled via Port register 1 bit 14 = 1, duty cycle may be out of spec. Under very rare conditions this may cause the attached device receive CRC errors.

Signed-off-by: Marek Behún kabel@kernel.org Cc: stable@vger.kernel.org # 5.4.x --- drivers/net/dsa/mv88e6xxx/chip.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+)

diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c index 88f479dc328c..901929f96b38 100644 --- a/drivers/net/dsa/mv88e6xxx/chip.c +++ b/drivers/net/dsa/mv88e6xxx/chip.c @@ -3674,6 +3674,21 @@ static int mv88e6xxx_stats_setup(struct mv88e6xxx_chip *chip) return mv88e6xxx_g1_stats_clear(chip); }

+static int mv88e6320_setup_errata(struct mv88e6xxx_chip *chip) +{ + u16 dummy; + int err; + + /* Workaround for erratum + * 3.3 RGMII timing may be out of spec when transmit delay is enabled + */ + err = mv88e6xxx_port_hidden_write(chip, 0, 0xf, 0x7, 0xe000); + if (err) + return err; + + return mv88e6xxx_port_hidden_read(chip, 0, 0xf, 0x7, &dummy); +} + /* Check if the errata has already been applied. */ static bool mv88e6390_setup_errata_applied(struct mv88e6xxx_chip *chip) { @@ -5130,6 +5145,7 @@ static const struct mv88e6xxx_ops mv88e6290_ops = {

static const struct mv88e6xxx_ops mv88e6320_ops = { /* MV88E6XXX_FAMILY_6320 */ + .setup_errata = mv88e6320_setup_errata, .ieee_pri_map = mv88e6085_g1_ieee_pri_map, .ip_pri_map = mv88e6085_g1_ip_pri_map, .irl_init_all = mv88e6352_g2_irl_init_all, @@ -5182,6 +5198,7 @@ static const struct mv88e6xxx_ops mv88e6320_ops = {

static const struct mv88e6xxx_ops mv88e6321_ops = { /* MV88E6XXX_FAMILY_6320 */ + .setup_errata = mv88e6320_setup_errata, .ieee_pri_map = mv88e6085_g1_ieee_pri_map, .ip_pri_map = mv88e6085_g1_ip_pri_map, .irl_init_all = mv88e6352_g2_irl_init_all,