* [PATCH v2] net: sh_eth: fix mdio access in sh_eth_close() for R-Car Gen2 and RZ/A1 SoCs
@ 2019-05-28 4:10 Yoshihiro Shimoda
2019-05-29 20:25 ` David Miller
2019-06-05 18:19 ` Sergei Shtylyov
0 siblings, 2 replies; 3+ messages in thread
From: Yoshihiro Shimoda @ 2019-05-28 4:10 UTC (permalink / raw)
To: sergei.shtylyov, davem; +Cc: netdev, linux-renesas-soc, Yoshihiro Shimoda
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(+)
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);
}
--
2.7.4
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v2] net: sh_eth: fix mdio access in sh_eth_close() for R-Car Gen2 and RZ/A1 SoCs
2019-05-28 4:10 [PATCH v2] net: sh_eth: fix mdio access in sh_eth_close() for R-Car Gen2 and RZ/A1 SoCs Yoshihiro Shimoda
@ 2019-05-29 20:25 ` David Miller
2019-06-05 18:19 ` Sergei Shtylyov
1 sibling, 0 replies; 3+ messages in thread
From: David Miller @ 2019-05-29 20:25 UTC (permalink / raw)
To: yoshihiro.shimoda.uh; +Cc: sergei.shtylyov, netdev, linux-renesas-soc
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.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v2] net: sh_eth: fix mdio access in sh_eth_close() for R-Car Gen2 and RZ/A1 SoCs
2019-05-28 4:10 [PATCH v2] net: sh_eth: fix mdio access in sh_eth_close() for R-Car Gen2 and RZ/A1 SoCs Yoshihiro Shimoda
2019-05-29 20:25 ` David Miller
@ 2019-06-05 18:19 ` Sergei Shtylyov
1 sibling, 0 replies; 3+ messages in thread
From: Sergei Shtylyov @ 2019-06-05 18:19 UTC (permalink / raw)
To: Yoshihiro Shimoda, davem; +Cc: netdev, linux-renesas-soc
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
^ permalink raw reply [flat|nested] 3+ messages in thread
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2019-05-28 4:10 [PATCH v2] net: sh_eth: fix mdio access in sh_eth_close() for R-Car Gen2 and RZ/A1 SoCs Yoshihiro Shimoda
2019-05-29 20:25 ` David Miller
2019-06-05 18:19 ` Sergei Shtylyov
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