RE: [PATCH 2/3] net: ethernet: add c45 PHY support in MDIO read/write functions.

[Parshuram Raju Thombare]

>On Fri, Feb 22, 2019 at 08:12:42PM +0000, Parshuram Thombare wrote:
>> This patch modify MDIO read/write functions to support communication
>> with C45 PHY in Cadence ethernet controller driver.
>>
>> Signed-off-by: Parshuram Thombare <pthombar@xxxxxxxxxxx>
>> ---
>>  drivers/net/ethernet/cadence/macb.h      |   15 +++++--
>>  drivers/net/ethernet/cadence/macb_main.c |   61
>++++++++++++++++++++++++-----
>>  2 files changed, 61 insertions(+), 15 deletions(-)
>>
>> diff --git a/drivers/net/ethernet/cadence/macb.h
>> b/drivers/net/ethernet/cadence/macb.h
>> index bed4ded..59c23e0 100644
>> --- a/drivers/net/ethernet/cadence/macb.h
>> +++ b/drivers/net/ethernet/cadence/macb.h
>> @@ -636,10 +636,17 @@
>>  #define GEM_CLK_DIV96				5
>>
>>  /* Constants for MAN register */
>> -#define MACB_MAN_SOF				1
>> -#define MACB_MAN_WRITE				1
>> -#define MACB_MAN_READ				2
>> -#define MACB_MAN_CODE				2
>> +#define MACB_MAN_C22_SOF                        1
>> +#define MACB_MAN_C22_WRITE                      1
>> +#define MACB_MAN_C22_READ                       2
>> +#define MACB_MAN_C22_CODE                       2
>> +
>> +#define MACB_MAN_C45_SOF                        0
>> +#define MACB_MAN_C45_ADDR                       0
>> +#define MACB_MAN_C45_WRITE                      1
>> +#define MACB_MAN_C45_POST_READ_INCR             2
>> +#define MACB_MAN_C45_READ                       3
>> +#define MACB_MAN_C45_CODE                       2
>>
>>  /* Capability mask bits */
>>  #define MACB_CAPS_ISR_CLEAR_ON_WRITE		0x00000001
>> diff --git a/drivers/net/ethernet/cadence/macb_main.c
>> b/drivers/net/ethernet/cadence/macb_main.c
>> index 4f4f8e5..2494abf 100644
>> --- a/drivers/net/ethernet/cadence/macb_main.c
>> +++ b/drivers/net/ethernet/cadence/macb_main.c
>> @@ -323,11 +323,30 @@ static int macb_mdio_read(struct mii_bus *bus, int
>mii_id, int regnum)
>>  	struct macb *bp = bus->priv;
>>  	int value;
>>
>> -	macb_writel(bp, MAN, (MACB_BF(SOF, MACB_MAN_SOF)
>> -			      | MACB_BF(RW, MACB_MAN_READ)
>> -			      | MACB_BF(PHYA, mii_id)
>> -			      | MACB_BF(REGA, regnum)
>> -			      | MACB_BF(CODE, MACB_MAN_CODE)));
>> +	if (regnum & MII_ADDR_C45) {
>> +		macb_writel(bp, MAN, (MACB_BF(SOF, MACB_MAN_C45_SOF)
>> +				| MACB_BF(RW, MACB_MAN_C45_ADDR)
>> +				| MACB_BF(PHYA, mii_id)
>> +				| MACB_BF(REGA, (regnum >> 16) & 0x1F)
>> +				| MACB_BF(DATA, regnum & 0xFFFF)
>> +				| MACB_BF(CODE, MACB_MAN_C45_CODE)));
>> +
>> +	/* wait for end of transfer */
>> +	while (!MACB_BFEXT(IDLE, macb_readl(bp, NSR)))
>> +		cpu_relax();
>
>You need a timeout here, and anywhere you wait for the hardware to complete.
>Try to make use of readx_poll_timeout() variants.
>
>	  Andrew
Yes, I will add timeout here.

Regards,
Parshuram Thombare