On 02/26/2018 12:08 PM, Grygorii Strashko wrote:
> Hi Florian,
>
> The TI CPSW driver produces warning as below when booted in switch mode:
> [ 8.882295] sysfs: cannot create duplicate filename
> '/devices/platform/44000000.ocp/48484000.ethernet/net/eth0/phydev'
> [ 8.999859] CPU: 1 PID: 356 Comm: systemd-network Not tainted
> 4.16.0-rc3-00010-g6cc3ff6-dirty #225
> ...
> [ 9.012352] Hardware name: Generic DRA74X (Flattened Device Tree)
> [ 9.018901] Backtrace:
> [ 9.021376] [<c010c918>] (dump_backtrace) from [<c010cbe8>]
> (show_stack+0x18/0x1c)
> [ 9.028986] r7:ed036240 r6:60070013 r5:00000000 r4:c0d598a0
> [ 9.034684] [<c010cbd0>] (show_stack) from [<c088e1f0>]
> (dump_stack+0x8c/0xa0)
> [ 9.041954] [<c088e164>] (dump_stack) from [<c02ba59c>]
> (sysfs_warn_dup+0x60/0x6c)
> [ 9.049564] r7:ed036240 r6:ed036240 r5:c0b579bc r4:ed10c000
> [ 9.055264] [<c02ba53c>] (sysfs_warn_dup) from [<c02ba930>]
> (sysfs_do_create_link_sd+0xbc/0xc4)
> [ 9.064006] r7:ed036240 r6:ffffffef r5:00000000 r4:ed034660
> [ 9.069701] [<c02ba874>] (sysfs_do_create_link_sd) from [<c02ba968>]
> (sysfs_create_link+0x30/0x3c)
> [ 9.078706] r9:00000008 r8:00000000 r7:ed02f008 r6:ee015ae8 r5:ee015800
> r4:ed02f000
> [ 9.086497] [<c02ba938>] (sysfs_create_link) from [<c060f070>]
> (phy_attach_direct+0x180/0x1f4)
> [ 9.095163] [<c060eef0>] (phy_attach_direct) from [<c060f1cc>]
> (phy_connect_direct+0x1c/0x54)
> [ 9.103735] r10:00000001 r9:ee015d0c r8:00000008 r7:c062e84c r6:c062e84c
> r5:ed02f000
> [ 9.111609] r4:ed02f000 r3:00000008
> [ 9.115217] [<c060f1b0>] (phy_connect_direct) from [<c060f250>]
> (phy_connect+0x4c/0x80)
> [ 9.123270] r7:c062e84c r6:ee015800 r5:ed02f000 r4:ee693664
> [ 9.128969] [<c060f204>] (phy_connect) from [<c062abc8>]
> (cpsw_slave_open+0x21c/0x274)
> [ 9.136926] r9:ee015d0c r8:ee015d00 r7:ed018a10 r6:ee015800 r5:ee015d00
> r4:ed032630
> [ 9.144715] [<c062a9ac>] (cpsw_slave_open) from [<c062b28c>]
> (cpsw_ndo_open+0x158/0x55c)
> [ 9.152860] r10:00000001 r9:00000000 r8:ee015d00 r7:c0d04c48 r6:ee015800
> r5:ed018a10
> [ 9.160730] r4:ed032630
> [ 9.163291] [<c062b134>] (cpsw_ndo_open) from [<c0765350>]
> (__dev_open+0xd4/0x158)
> [ 9.170900] r10:00000000 r9:ec885db4 r8:ee01582c r7:c09a9c00 r6:00000000
> r5:c0d04c48
> [ 9.178768] r4:ee015800
> [ 9.181326] [<c076527c>] (__dev_open) from [<c0765748>]
> (__dev_change_flags+0x174/0x1c0)
>
> The reason of the warning is that in switch mode CPSW drivers is connecting
> two Net PHYs to
> a single network device (it has been done this way when driver was initially
> introduced), so
> now it produces warning during boot because of commits:
>
> 5568363f0cb3 ("net: phy: Create sysfs reciprocal links for
> attached_dev/phydev"
> a3995460491d ("net: phy: Relax error checking on sysfs_create_link()"
> ^ both went in v4.13
>
> Honestly, I'm not sure how to fix it the best way (the simplest fix is
> below), taking into account
> that we are not ready to do big reworks in CPSW driver.
The CPSW driver is duplicating a fair amount of what the DSA subsystem
does properly without breaking any assumptions about the 1:1 mapping
that can exist between a network device and PHY device. Having a PHY
device without a network device is fine in premise, although discouraged.
Migrating to DSA is certainly a big task, but I would strongly encourage
you to consider doing it, since that would solve this problem, and
probably many more.
>
> Sry, for the late report - in LKML most of dual port TI platforms configured
> to work in
> dual mac mode, therefore two network devices are created and warning not
> displayed.
>
--
Florian
