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net: marvell: mvpp2: only reprogram what is necessary on mac_config 

mac_config() can be called at any point, and the expected behaviour
from MAC drivers is to only reprogram when necessary - and certainly
avoid taking the link down on every call.

Unfortunately, mvpp2 does exactly that - it takes the link down, and
reprograms everything, and then releases the forced-link down.

This is bad, it can cause the link to bounce:

- SFP detects signal, disables LOS indication.
- SFP code calls into phylink, calling phylink_sfp_link_up() which
  triggers a resolve.
- phylink_resolve() calls phylink_get_mac_state() and finds the MAC
  reporting link up.
- phylink wants to configure the pause mode on the MAC, so calls
  phylink_mac_config()
- mvpp2 takes the link down temporarily, generating a MAC link down
  event followed by another MAC link event.
- phylink calls mac_link_up() and then processes the MAC link down
  event.
- phylink_resolve() gets called again, registers the link down, and
  calls mach_link_down() before re-running itself.
- phylink_resolve() starts again at step 3 above.  This sequence
  repeats.

GMAC versions prior to mvpp2 do not require the link to be taken down
except when certain link properties (eg, switching between SGMII and
1000base-X mode, or enabling/disabling in-band negotiation) are
changed.  Implement this for mvpp2.

Tested-by: Sven Auhagen <sven.auhagen@voleatech.de>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
hifive-unleashed-5.1
Russell King 2019-02-08 15:35:49 +00:00 committed by David S. Miller
parent 316734fdcf
commit d14e078f23
1 changed files with 35 additions and 23 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

58
drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
View File

@ -4534,29 +4534,21 @@ static void mvpp2_xlg_config(struct mvpp2_port *port, unsigned int mode,
static void mvpp2_gmac_config(struct mvpp2_port *port, unsigned int mode,
const struct phylink_link_state *state)
{
u32 an, ctrl0, ctrl2, ctrl4;
u32 old_ctrl2;
u32 old_an, an;
u32 old_ctrl0, ctrl0;
u32 old_ctrl2, ctrl2;
u32 old_ctrl4, ctrl4;
an = readl(port->base + MVPP2_GMAC_AUTONEG_CONFIG);
ctrl0 = readl(port->base + MVPP2_GMAC_CTRL_0_REG);
ctrl2 = readl(port->base + MVPP2_GMAC_CTRL_2_REG);
ctrl4 = readl(port->base + MVPP22_GMAC_CTRL_4_REG);
old_ctrl2 = ctrl2;
/* Force link down */
an &= ~MVPP2_GMAC_FORCE_LINK_PASS;
an |= MVPP2_GMAC_FORCE_LINK_DOWN;
writel(an, port->base + MVPP2_GMAC_AUTONEG_CONFIG);
/* Set the GMAC in a reset state */
ctrl2 |= MVPP2_GMAC_PORT_RESET_MASK;
writel(ctrl2, port->base + MVPP2_GMAC_CTRL_2_REG);
old_an = an = readl(port->base + MVPP2_GMAC_AUTONEG_CONFIG);
old_ctrl0 = ctrl0 = readl(port->base + MVPP2_GMAC_CTRL_0_REG);
old_ctrl2 = ctrl2 = readl(port->base + MVPP2_GMAC_CTRL_2_REG);
old_ctrl4 = ctrl4 = readl(port->base + MVPP22_GMAC_CTRL_4_REG);
an &= ~(MVPP2_GMAC_CONFIG_MII_SPEED | MVPP2_GMAC_CONFIG_GMII_SPEED |
MVPP2_GMAC_AN_SPEED_EN | MVPP2_GMAC_FC_ADV_EN |
MVPP2_GMAC_FC_ADV_ASM_EN | MVPP2_GMAC_FLOW_CTRL_AUTONEG |
MVPP2_GMAC_CONFIG_FULL_DUPLEX | MVPP2_GMAC_AN_DUPLEX_EN);
MVPP2_GMAC_CONFIG_FULL_DUPLEX | MVPP2_GMAC_AN_DUPLEX_EN |
MVPP2_GMAC_IN_BAND_AUTONEG | MVPP2_GMAC_IN_BAND_AUTONEG_BYPASS);
ctrl0 &= ~MVPP2_GMAC_PORT_TYPE_MASK;
ctrl2 &= ~(MVPP2_GMAC_INBAND_AN_MASK | MVPP2_GMAC_PORT_RESET_MASK |
MVPP2_GMAC_PCS_ENABLE_MASK);
@ -4623,7 +4615,8 @@ static void mvpp2_gmac_config(struct mvpp2_port *port, unsigned int mode,
*/
ctrl0 |= MVPP2_GMAC_PORT_TYPE_MASK;
an &= ~(MVPP2_GMAC_FORCE_LINK_DOWN | MVPP2_GMAC_FORCE_LINK_PASS);
an |= MVPP2_GMAC_CONFIG_GMII_SPEED |
an |= MVPP2_GMAC_IN_BAND_AUTONEG |
MVPP2_GMAC_CONFIG_GMII_SPEED |
MVPP2_GMAC_CONFIG_FULL_DUPLEX;
if (state->pause & MLO_PAUSE_AN && state->an_enabled) {
@ -4636,10 +4629,29 @@ static void mvpp2_gmac_config(struct mvpp2_port *port, unsigned int mode,
}
}
writel(ctrl0, port->base + MVPP2_GMAC_CTRL_0_REG);
writel(ctrl2, port->base + MVPP2_GMAC_CTRL_2_REG);
writel(ctrl4, port->base + MVPP22_GMAC_CTRL_4_REG);
writel(an, port->base + MVPP2_GMAC_AUTONEG_CONFIG);
if ((old_ctrl0 ^ ctrl0) & MVPP2_GMAC_PORT_TYPE_MASK ||
(old_ctrl2 ^ ctrl2) & MVPP2_GMAC_INBAND_AN_MASK ||
(old_an ^ an) & MVPP2_GMAC_IN_BAND_AUTONEG) {
/* Force link down */
old_an &= ~MVPP2_GMAC_FORCE_LINK_PASS;
old_an |= MVPP2_GMAC_FORCE_LINK_DOWN;
writel(old_an, port->base + MVPP2_GMAC_AUTONEG_CONFIG);
/* Set the GMAC in a reset state - do this in a way that
* ensures we clear it below.
*/
old_ctrl2 |= MVPP2_GMAC_PORT_RESET_MASK;
writel(old_ctrl2, port->base + MVPP2_GMAC_CTRL_2_REG);
}
if (old_ctrl0 != ctrl0)
writel(ctrl0, port->base + MVPP2_GMAC_CTRL_0_REG);
if (old_ctrl2 != ctrl2)
writel(ctrl2, port->base + MVPP2_GMAC_CTRL_2_REG);
if (old_ctrl4 != ctrl4)
writel(ctrl4, port->base + MVPP22_GMAC_CTRL_4_REG);
if (old_an != an)
writel(an, port->base + MVPP2_GMAC_AUTONEG_CONFIG);
if (old_ctrl2 & MVPP2_GMAC_PORT_RESET_MASK) {
while (readl(port->base + MVPP2_GMAC_CTRL_2_REG) &