From mboxrd@z Thu Jan 1 00:00:00 1970 From: Heiner Kallweit Subject: Re: [PATCH net] net: phy: micrel: set soft_reset callback to genphy_soft_reset for KSZ9031 Date: Thu, 10 Jan 2019 20:41:08 +0100 Message-ID: References: <6d3b1dce-7633-51a1-0556-97cd03304c2c@gmail.com> <6ad9a9c8-3f65-b16e-19d1-b54efb3a0b70@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: "netdev@vger.kernel.org" , Tony Lindgren To: Florian Fainelli , Andrew Lunn , David Miller Return-path: Received: from mail-wr1-f67.google.com ([209.85.221.67]:42202 "EHLO mail-wr1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727653AbfAJTlR (ORCPT ); Thu, 10 Jan 2019 14:41:17 -0500 Received: by mail-wr1-f67.google.com with SMTP id q18so12715468wrx.9 for ; Thu, 10 Jan 2019 11:41:16 -0800 (PST) In-Reply-To: <6ad9a9c8-3f65-b16e-19d1-b54efb3a0b70@gmail.com> Content-Language: en-US Sender: netdev-owner@vger.kernel.org List-ID: On 10.01.2019 20:24, Florian Fainelli wrote: > On 1/10/19 11:22 AM, Heiner Kallweit wrote: >> So far genphy_soft_reset was used automatically if the PHY driver >> didn't implement the soft_reset callback. This changed with the >> mentioned commit and broke KSZ9031. To fix this configure the >> KSZ9031 PHY driver to use genphy_soft_reset. >> >> Fixes: 6e2d85ec0559 ("net: phy: Stop with excessive soft reset") >> Reported-by: Tony Lindgren >> Signed-off-by: Heiner Kallweit > > Thanks a lot for following up with the people at TI on this. We should > really get a better understanding of what the issue is, and whether > there is a possibly better workaround that could be developed which is > not just as hard as a big hammer software reset. Maybe we can get some > people/contacts at Micrel to help here. > In ksz9031_config_init() quite some settings are done and IMO it's not that unusual that it takes a soft reset for such settings to become effective. But I agree it would be nice if somebody from the PHY vendor could comment on whether a soft reset is actually needed. Not sure who has a contact to Microchip. If the feedback takes time it may be better to apply the soft reset as fix and replace it later in case we have a less intrusive option. >> --- >> drivers/net/phy/micrel.c | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c >> index c33384710..7828d17f0 100644 >> --- a/drivers/net/phy/micrel.c >> +++ b/drivers/net/phy/micrel.c >> @@ -1070,6 +1070,7 @@ static struct phy_driver ksphy_driver[] = { >> .driver_data = &ksz9021_type, >> .probe = kszphy_probe, >> .config_init = ksz9031_config_init, >> + .soft_reset = genphy_soft_reset, >> .read_status = ksz9031_read_status, >> .ack_interrupt = kszphy_ack_interrupt, >> .config_intr = kszphy_config_intr, >> > >