diff options
Diffstat (limited to 'drivers/net/ethernet/ibm/emac/core.c')
| -rw-r--r-- | drivers/net/ethernet/ibm/emac/core.c | 26 |
1 files changed, 22 insertions, 4 deletions
diff --git a/drivers/net/ethernet/ibm/emac/core.c b/drivers/net/ethernet/ibm/emac/core.c index b9df0cbd0a38..9571f7dad162 100644 --- a/drivers/net/ethernet/ibm/emac/core.c +++ b/drivers/net/ethernet/ibm/emac/core.c @@ -342,6 +342,7 @@ static int emac_reset(struct emac_instance *dev) { struct emac_regs __iomem *p = dev->emacp; int n = 20; + bool __maybe_unused try_internal_clock = false; DBG(dev, "reset" NL); @@ -354,6 +355,7 @@ static int emac_reset(struct emac_instance *dev) } #ifdef CONFIG_PPC_DCR_NATIVE +do_retry: /* * PPC460EX/GT Embedded Processor Advanced User's Manual * section 28.10.1 Mode Register 0 (EMACx_MR0) states: @@ -361,10 +363,19 @@ static int emac_reset(struct emac_instance *dev) * of the EMAC. If none is present, select the internal clock * (SDR0_ETH_CFG[EMACx_PHY_CLK] = 1). * After a soft reset, select the external clock. + * + * The AR8035-A PHY Meraki MR24 does not provide a TX Clk if the + * ethernet cable is not attached. This causes the reset to timeout + * and the PHY detection code in emac_init_phy() is unable to + * communicate and detect the AR8035-A PHY. As a result, the emac + * driver bails out early and the user has no ethernet. + * In order to stay compatible with existing configurations, the + * driver will temporarily switch to the internal clock, after + * the first reset fails. */ if (emac_has_feature(dev, EMAC_FTR_460EX_PHY_CLK_FIX)) { - if (dev->phy_address == 0xffffffff && - dev->phy_map == 0xffffffff) { + if (try_internal_clock || (dev->phy_address == 0xffffffff && + dev->phy_map == 0xffffffff)) { /* No PHY: select internal loop clock before reset */ dcri_clrset(SDR0, SDR0_ETH_CFG, 0, SDR0_ETH_CFG_ECS << dev->cell_index); @@ -382,8 +393,15 @@ static int emac_reset(struct emac_instance *dev) #ifdef CONFIG_PPC_DCR_NATIVE if (emac_has_feature(dev, EMAC_FTR_460EX_PHY_CLK_FIX)) { - if (dev->phy_address == 0xffffffff && - dev->phy_map == 0xffffffff) { + if (!n && !try_internal_clock) { + /* first attempt has timed out. */ + n = 20; + try_internal_clock = true; + goto do_retry; + } + + if (try_internal_clock || (dev->phy_address == 0xffffffff && + dev->phy_map == 0xffffffff)) { /* No PHY: restore external clock source after reset */ dcri_clrset(SDR0, SDR0_ETH_CFG, SDR0_ETH_CFG_ECS << dev->cell_index, 0); |