Message ID | 1559016646-7293-1-git-send-email-yoshihiro.shimoda.uh@renesas.com |
---|---|
State | Accepted |
Delegated to: | David Miller |
Headers | show |
Series | [v2] net: sh_eth: fix mdio access in sh_eth_close() for R-Car Gen2 and RZ/A1 SoCs | expand |
From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Date: Tue, 28 May 2019 13:10:46 +0900 > The sh_eth_close() resets the MAC and then calls phy_stop() > so that mdio read access result is incorrect without any error > according to kernel trace like below: > > ifconfig-216 [003] .n.. 109.133124: mdio_access: ee700000.ethernet-ffffffff read phy:0x01 reg:0x00 val:0xffff > > According to the hardware manual, the RMII mode should be set to 1 > before operation the Ethernet MAC. However, the previous code was not > set to 1 after the driver issued the soft_reset in sh_eth_dev_exit() > so that the mdio read access result seemed incorrect. To fix the issue, > this patch adds a condition and set the RMII mode register in > sh_eth_dev_exit() for R-Car Gen2 and RZ/A1 SoCs. > > Note that when I have tried to move the sh_eth_dev_exit() calling > after phy_stop() on sh_eth_close(), but it gets worse (kernel panic > happened and it seems that a register is accessed while the clock is > off). > > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> > --- > Changes from v1 (https://patchwork.kernel.org/patch/10944265/): > - Revise the subject, commit log and the comment of the code. > - Move the RMII setting to right after soft_reset. Applied, thank you.
Hello! I've been meaning to look around this issue before replying to this respin but didn't notify DaveM, so he finally merged it... On 05/28/2019 07:10 AM, Yoshihiro Shimoda wrote: > The sh_eth_close() resets the MAC and then calls phy_stop() > so that mdio read access result is incorrect without any error > according to kernel trace like below: > > ifconfig-216 [003] .n.. 109.133124: mdio_access: ee700000.ethernet-ffffffff read phy:0x01 reg:0x00 val:0xffff > > According to the hardware manual, the RMII mode should be set to 1 > before operation the Ethernet MAC. However, the previous code was not > set to 1 after the driver issued the soft_reset in sh_eth_dev_exit() > so that the mdio read access result seemed incorrect. To fix the issue, > this patch adds a condition and set the RMII mode register in > sh_eth_dev_exit() for R-Car Gen2 and RZ/A1 SoCs. I told you RZ/G1, not RZ/A1. The latter has its own data structure and different register layout. > Note that when I have tried to move the sh_eth_dev_exit() calling > after phy_stop() on sh_eth_close(), but it gets worse (kernel panic > happened and it seems that a register is accessed while the clock is > off). I've reproduced it but still don't know why that happens. > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> > --- > Changes from v1 (https://patchwork.kernel.org/patch/10944265/): > - Revise the subject, commit log and the comment of the code. > - Move the RMII setting to right after soft_reset. > > drivers/net/ethernet/renesas/sh_eth.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c > index 6354f19..7ba35a0 100644 > --- a/drivers/net/ethernet/renesas/sh_eth.c > +++ b/drivers/net/ethernet/renesas/sh_eth.c > @@ -1594,6 +1594,10 @@ static void sh_eth_dev_exit(struct net_device *ndev) > sh_eth_get_stats(ndev); > mdp->cd->soft_reset(ndev); > > + /* Set the RMII mode again if required */ When I asked for more details, I was meaning this comment. Thanks for telling me about the gory details anyway. :-) > + if (mdp->cd->rmiimode) > + sh_eth_write(ndev, 0x1, RMIIMODE); > + > /* Set MAC address again */ > update_mac_address(ndev); > } MBR, Sergei
diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c index 6354f19..7ba35a0 100644 --- a/drivers/net/ethernet/renesas/sh_eth.c +++ b/drivers/net/ethernet/renesas/sh_eth.c @@ -1594,6 +1594,10 @@ static void sh_eth_dev_exit(struct net_device *ndev) sh_eth_get_stats(ndev); mdp->cd->soft_reset(ndev); + /* Set the RMII mode again if required */ + if (mdp->cd->rmiimode) + sh_eth_write(ndev, 0x1, RMIIMODE); + /* Set MAC address again */ update_mac_address(ndev); }
The sh_eth_close() resets the MAC and then calls phy_stop() so that mdio read access result is incorrect without any error according to kernel trace like below: ifconfig-216 [003] .n.. 109.133124: mdio_access: ee700000.ethernet-ffffffff read phy:0x01 reg:0x00 val:0xffff According to the hardware manual, the RMII mode should be set to 1 before operation the Ethernet MAC. However, the previous code was not set to 1 after the driver issued the soft_reset in sh_eth_dev_exit() so that the mdio read access result seemed incorrect. To fix the issue, this patch adds a condition and set the RMII mode register in sh_eth_dev_exit() for R-Car Gen2 and RZ/A1 SoCs. Note that when I have tried to move the sh_eth_dev_exit() calling after phy_stop() on sh_eth_close(), but it gets worse (kernel panic happened and it seems that a register is accessed while the clock is off). Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> --- Changes from v1 (https://patchwork.kernel.org/patch/10944265/): - Revise the subject, commit log and the comment of the code. - Move the RMII setting to right after soft_reset. drivers/net/ethernet/renesas/sh_eth.c | 4 ++++ 1 file changed, 4 insertions(+)