-----Original Message----- From: Russell King linux@armlinux.org.uk Sent: Wednesday, January 12, 2022 9:13 PM To: Ismail, Mohammad Athari mohammad.athari.ismail@intel.com Cc: Andrew Lunn andrew@lunn.ch; David S . Miller davem@davemloft.net; Jakub Kicinski kuba@kernel.org; Oleksij Rempel linux@rempel-privat.de; Heiner Kallweit hkallweit1@gmail.com; netdev@vger.kernel.org; linux- kernel@vger.kernel.org; stable@vger.kernel.org Subject: Re: [PATCH net v2] net: phy: marvell: add Marvell specific PHY loopback
On Wed, Jan 12, 2022 at 05:33:44PM +0800, Mohammad Athari Bin Ismail wrote:
+static int marvell_loopback(struct phy_device *phydev, bool enable) {
- if (enable) {
u16 bmcr_ctl = 0, mscr2_ctl = 0;if (phydev->speed == SPEED_1000)bmcr_ctl = BMCR_SPEED1000;else if (phydev->speed == SPEED_100)bmcr_ctl = BMCR_SPEED100;if (phydev->duplex == DUPLEX_FULL)bmcr_ctl |= BMCR_FULLDPLX;phy_modify(phydev, MII_BMCR, ~0, bmcr_ctl);Is there any point in doing a read-modify-write here if you're just setting all bits in the register? Wouldn't phy_write() be more appropriate? What about error handing?
Yes, you're right. phy_write() is more suitable. And will add error handling as well. Will include them in v3 patch.
if (phydev->speed == SPEED_1000)mscr2_ctl = BMCR_SPEED1000;else if (phydev->speed == SPEED_100)mscr2_ctl = BMCR_SPEED100;phy_modify_paged(phydev, MII_MARVELL_MSCR_PAGE,MII_88E1510_MSCR_2, BMCR_SPEED1000 |BMCR_SPEED100, mscr2_ctl);
I believe this also need error handling.
/* Need soft reset to have speed configuration takes effect*/
genphy_soft_reset(phydev);
Ditto.
/* FIXME: Based on trial and error test, it seem 1G need tohave
* delay between soft reset and loopback enablement.*/if (phydev->speed == SPEED_1000)msleep(1000);return phy_modify(phydev, MII_BMCR, BMCR_LOOPBACK,BMCR_LOOPBACK);- } else {
phy_modify(phydev, MII_BMCR, BMCR_LOOPBACK, 0);Error handling?
Will add it in v3 patch.
-Athari-
Thanks.
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