> -----Original Message----- > From: Philipp Zabel [mailto:p.zabel@xxxxxxxxxxxxxx] > Sent: 2022年3月21日 4:15 PM > To: Dylan Hung <dylan_hung@xxxxxxxxxxxxxx>; robh+dt@xxxxxxxxxx; > joel@xxxxxxxxx; andrew@xxxxxxxx; andrew@xxxxxxx; hkallweit1@xxxxxxxxx; > linux@xxxxxxxxxxxxxxx; davem@xxxxxxxxxxxxx; kuba@xxxxxxxxxx; > pabeni@xxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-aspeed@xxxxxxxxxxxxxxxx; > linux-kernel@xxxxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx > Cc: BMC-SW <BMC-SW@xxxxxxxxxxxxxx>; stable@xxxxxxxxxxxxxxx > Subject: Re: [PATCH 1/2] net: mdio: add reset deassertion for Aspeed MDIO > > Hi Dylan, > > On Mo, 2022-03-21 at 15:01 +0800, Dylan Hung wrote: > > Add reset deassertion for Aspeed MDIO. There are 4 MDIO controllers > > embedded in Aspeed AST2600 SOC and share one reset control register > > SCU50[3]. So devm_reset_control_get_shared is used in this change. > > > > Signed-off-by: Dylan Hung <dylan_hung@xxxxxxxxxxxxxx> > > Cc: stable@xxxxxxxxxxxxxxx > > --- > > drivers/net/mdio/mdio-aspeed.c | 8 ++++++++ > > 1 file changed, 8 insertions(+) > > > > diff --git a/drivers/net/mdio/mdio-aspeed.c b/drivers/net/mdio/mdio- > > aspeed.c index e2273588c75b..8ac262a12d13 100644 > > --- a/drivers/net/mdio/mdio-aspeed.c > > +++ b/drivers/net/mdio/mdio-aspeed.c > > @@ -3,6 +3,7 @@ > > > > #include <linux/bitfield.h> > > #include <linux/delay.h> > > +#include <linux/reset.h> > > #include <linux/iopoll.h> > > #include <linux/mdio.h> > > #include <linux/module.h> > > @@ -37,6 +38,7 @@ > > > > struct aspeed_mdio { > > void __iomem *base; > > + struct reset_control *reset; > > }; > > > > static int aspeed_mdio_read(struct mii_bus *bus, int addr, int > > regnum) > > @@ -120,6 +122,12 @@ static int aspeed_mdio_probe(struct > > platform_device *pdev) > > if (IS_ERR(ctx->base)) > > return PTR_ERR(ctx->base); > > > > + ctx->reset = devm_reset_control_get_shared(&pdev->dev, NULL); > > The device tree bindings should have a required reset control property > documented before this is added. > OK, I will add a commit for the document in V2. > > + if (IS_ERR(ctx->reset)) > > + return PTR_ERR(ctx->reset); > > + > > + reset_control_deassert(ctx->reset); > > + > > This is missing a corresponding reset_control_assert() in > aspeed_mdio_remove() and in the error path of of_mdiobus_register(). > That would allow to assert the reset line again after all MDIO controllers are > unbound. Thank you for your comment. I will fix it in V2. > > regards > Philipp -- Dylan
