It appears that the single port Ether controllers having TSU (like SH7734/ R8A7740) need the same kind of treating in sh_eth_tsu_init() as R7S72100 currently has -- they also don't have the TSU registers related e.g. to passing the frames between ports. Add the 'sh_eth_cpu_data::dual_port' flag and use it as a new criterion for taking a "short path" in the TSU init sequence in order to avoid writing to the non-existant registers... Fixes: f0e81fecd4f8 ("net: sh_eth: Add support SH7734") Fixes: 73a0d907301e ("net: sh_eth: add support R8A7740") Signed-off-by: Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx> --- David, I'm submitting this patch against the 'net-next.git' repo since nothing seems to explode when writing to the non-existing TSU registers. Whether to apply this to 'net.git' instead is up to you... drivers/net/ethernet/renesas/sh_eth.c | 6 +++++- drivers/net/ethernet/renesas/sh_eth.h | 1 + 2 files changed, 6 insertions(+), 1 deletion(-) Index: net-next/drivers/net/ethernet/renesas/sh_eth.c =================================================================== --- net-next.orig/drivers/net/ethernet/renesas/sh_eth.c +++ net-next/drivers/net/ethernet/renesas/sh_eth.c @@ -752,6 +752,7 @@ static struct sh_eth_cpu_data sh7757_dat .rpadir = 1, .rpadir_value = 2 << 16, .rtrate = 1, + .dual_port = 1, }; #define SH_GIGA_ETH_BASE 0xfee00000UL @@ -830,6 +831,7 @@ static struct sh_eth_cpu_data sh7757_dat .no_trimd = 1, .no_ade = 1, .tsu = 1, + .dual_port = 1, }; /* SH7734 */ @@ -900,6 +902,7 @@ static struct sh_eth_cpu_data sh7763_dat .tsu = 1, .irq_flags = IRQF_SHARED, .magic = 1, + .dual_port = 1, }; static struct sh_eth_cpu_data sh7619_data = { @@ -932,6 +935,7 @@ static struct sh_eth_cpu_data sh771x_dat EESIPR_RRFIP | EESIPR_RTLFIP | EESIPR_RTSFIP | EESIPR_PREIP | EESIPR_CERFIP, .tsu = 1, + .dual_port = 1, }; static void sh_eth_set_default_cpu_data(struct sh_eth_cpu_data *cd) @@ -2915,7 +2919,7 @@ static int sh_eth_vlan_rx_kill_vid(struc /* SuperH's TSU register init function */ static void sh_eth_tsu_init(struct sh_eth_private *mdp) { - if (sh_eth_is_rz_fast_ether(mdp)) { + if (!mdp->cd->dual_port) { sh_eth_tsu_write(mdp, 0, TSU_TEN); /* Disable all CAM entry */ sh_eth_tsu_write(mdp, TSU_FWSLC_POSTENU | TSU_FWSLC_POSTENL, TSU_FWSLC); /* Enable POST registers */ Index: net-next/drivers/net/ethernet/renesas/sh_eth.h =================================================================== --- net-next.orig/drivers/net/ethernet/renesas/sh_eth.h +++ net-next/drivers/net/ethernet/renesas/sh_eth.h @@ -509,6 +509,7 @@ struct sh_eth_cpu_data { unsigned rmiimode:1; /* EtherC has RMIIMODE register */ unsigned rtrate:1; /* EtherC has RTRATE register */ unsigned magic:1; /* EtherC has ECMR.MPDE and ECSR.MPD */ + unsigned dual_port:1; /* Dual EtherC/E-DMAC */ }; struct sh_eth_private {