On Wed, Oct 28, 2020 at 11:14:27PM +0100, Marek Behún wrote:
> This adds support for multigig copper SFP modules from RollBall/Hilink.
> These modules have a specific way to access clause 45 registers of the
> internal PHY.
>
> We also need to wait at least 25 seconds after deasserting TX disable
> before accessing the PHY. The code waits for 30 seconds just to be sure.
Any ideas why it takes 25 seconds for the module to initialise - the
88x3310 startup is pretty fast in itself. However, it never amazes me
how broken SFP modules can be.
Extending T_WAIT is one way around this, and luckily I already catered
for the case where T_WAIT is extended beyond module_t_start_up.
Usual comment about line lengths...
>
> Signed-off-by: Marek Behún <ka...@kernel.org>
> Cc: Andrew Lunn <and...@lunn.ch>
> Cc: Russell King <rmk+ker...@armlinux.org.uk>
> ---
> drivers/net/phy/sfp.c | 72 ++++++++++++++++++++++++++++++++++++++-----
> 1 file changed, 65 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c
> index a392d5fc6ab4..379358f194ee 100644
> --- a/drivers/net/phy/sfp.c
> +++ b/drivers/net/phy/sfp.c
> @@ -165,6 +165,7 @@ static const enum gpiod_flags gpio_flags[] = {
> * on board (for a copper SFP) time to initialise.
> */
> #define T_WAIT msecs_to_jiffies(50)
> +#define T_WAIT_LONG_PHY msecs_to_jiffies(30000)
I think call this T_WAIT_ROLLBALL.
> @@ -1675,12 +1681,40 @@ static int sfp_cotsworks_fixup_check(struct sfp *sfp,
> struct sfp_eeprom_id *id)
> return 0;
> }
>
> +static int sfp_rollball_init_mdio(struct sfp *sfp)
> +{
> + u8 page, password[4];
> + int err;
> +
> + page = 3;
> +
> + err = sfp_write(sfp, true, SFP_PAGE, &page, 1);
> + if (err != 1) {
> + dev_err(sfp->dev, "Failed to set SFP page for RollBall MDIO
> access: %d\n", err);
> + return err;
> + }
> +
> + password[0] = 0xff;
> + password[1] = 0xff;
> + password[2] = 0xff;
> + password[3] = 0xff;
> +
> + err = sfp_write(sfp, true, 0x7b, password, 4);
> + if (err != 4) {
> + dev_err(sfp->dev, "Failed to write password for RollBall MDIO
> access: %d\n", err);
> + return err;
> + }
> +
> + return 0;
> +}
I think this needs to be done in the MDIO driver - if we have userspace
or otherwise expand what we're doing, relying on page 3 remaining
selected will be very fragile.
--
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!
