On 12/29/23 6:07 PM, claudiu beznea wrote: [...] >>>>> From: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx> >>>>> >>>>> CSR.OPS bits specify the current operating mode and (according to >>>>> documentation) they are updated by HW when the operating mode change >>>>> request is processed. To comply with this check CSR.OPS before proceeding. >>>>> >>>>> Commit introduces ravb_set_opmode() that does all the necessities for >>>>> setting the operating mode (set DMA.CCC and wait for CSR.OPS) and call it >>>>> where needed. This should comply with all the HW manuals requirements as >>>>> different manual variants specify that different modes need to be checked >>>>> in CSR.OPS when setting DMA.CCC. >>>>> >>>>> Fixes: c156633f1353 ("Renesas Ethernet AVB driver proper") >>>>> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx> >>>>> --- >>>>> drivers/net/ethernet/renesas/ravb_main.c | 52 ++++++++++++++---------- >>>>> 1 file changed, 31 insertions(+), 21 deletions(-) >>>>> >>>>> diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c >>>>> index 664eda4b5a11..ae99d035a3b6 100644 >>>>> --- a/drivers/net/ethernet/renesas/ravb_main.c >>>>> +++ b/drivers/net/ethernet/renesas/ravb_main.c >>>>> @@ -66,14 +66,15 @@ int ravb_wait(struct net_device *ndev, enum ravb_reg reg, u32 mask, u32 value) >>>>> return -ETIMEDOUT; >>>>> } >>>>> >>>>> -static int ravb_config(struct net_device *ndev) >>>>> +static int ravb_set_opmode(struct net_device *ndev, u32 opmode) >>>> >>>> Since you pass the complete CCC register value below, you should >>>> rather call the function ravb_set_ccc() and call the parameter opmode >>>> ccc. >>> >>> This will be confusing. E.g., if renaming it ravb_set_ccc() one would >>> expect to set any fields of CCC though this function but this is not true >>> as ravb_modify() in this function masks only CCC_OPC. The call of: >>> >>> error = ravb_set_opmode(ndev, CCC_OPC_CONFIG | CCC_GAC | CCC_CSEL_HPB); >>> >>> bellow is just to comply with datasheet requirements, previous code and at >>> the same time re-use this function. >> >> How about the following then (ugly... but does the job): >> >> /* Set operating mode */ >> if (opmode & ~CCC_OPC) >> ravb_write(ndev, opmode, CCC); >> else >> ravb_modify(ndev, CCC, CCC_OPC, opmode); >> >> Either that or just don't use ravb_set_opmode() when writing the whole >> 32-bit value below... > > This looks uglier to me... > > We have this discussion because of ccc_gac. For ccc_gac platforms we need > to set OPC, GAC, CSEL at the same time. This is how we can change the > operating mode to configuration mode in case we also need to configure GAC > (due to restrictions imposed by hardware). > > What I want to say is that setting GAC and CSEL along with CCC is part of > changing the operating mode to configuration mode for platforms supporting > GAC because of hardware limitations. After thinking about it once more, your description seems correct. But then we need something like this: static int ravb_set_opmode(struct net_device *ndev, u32 opmode) { u32 ccc_mask = CCC_OPC; u32 csr_ops = 1U << (opmode & CCC_OPC); int error; if (opmode & CCC_GAC) ccc_mask |= CCC_CSEL; /* Set operating mode */ ravb_modify(ndev, CCC, ccc_mask, opmode); /* Check if the operating mode is changed to the requested one */ error = ravb_wait(ndev, CSR, CSR_OPS, csr_ops); if (error) netdev_err(ndev, "failed to switch device to requested mode\n"); return error; } [...] MBR, Sergey