net: usb: ax88179_178a: fix failed operations during ax88179_reset
authorJose Ignacio Tornos Martinez <jtornosm@redhat.com>
Mon, 20 Nov 2023 12:06:29 +0000 (13:06 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sun, 3 Dec 2023 06:33:04 +0000 (07:33 +0100)
commit41eccb6e1c1d568d2ee108a12beef3399e55f7ea
tree5042b17b28229c044be0b3849b78333057305eba
parentd75f7c1bd8fd0144b766239838e250e5aee9e375
net: usb: ax88179_178a: fix failed operations during ax88179_reset

[ Upstream commit 0739af07d1d947af27c877f797cb82ceee702515 ]

Using generic ASIX Electronics Corp. AX88179 Gigabit Ethernet device,
the following test cycle has been implemented:
    - power on
    - check logs
    - shutdown
    - after detecting the system shutdown, disconnect power
    - after approximately 60 seconds of sleep, power is restored
Running some cycles, sometimes error logs like this appear:
    kernel: ax88179_178a 2-9:1.0 (unnamed net_device) (uninitialized): Failed to write reg index 0x0001: -19
    kernel: ax88179_178a 2-9:1.0 (unnamed net_device) (uninitialized): Failed to read reg index 0x0001: -19
    ...
These failed operation are happening during ax88179_reset execution, so
the initialization could not be correct.

In order to avoid this, we need to increase the delay after reset and
clock initial operations. By using these larger values, many cycles
have been run and no failed operations appear.

It would be better to check some status register to verify when the
operation has finished, but I do not have found any available information
(neither in the public datasheets nor in the manufacturer's driver). The
only available information for the necessary delays is the maufacturer's
driver (original values) but the proposed values are not enough for the
tested devices.

Fixes: e2ca90c276e1f ("ax88179_178a: ASIX AX88179_178A USB 3.0/2.0 to gigabit ethernet adapter driver")
Reported-by: Herb Wei <weihao.bj@ieisystem.com>
Tested-by: Herb Wei <weihao.bj@ieisystem.com>
Signed-off-by: Jose Ignacio Tornos Martinez <jtornosm@redhat.com>
Link: https://lore.kernel.org/r/20231120120642.54334-1-jtornosm@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/net/usb/ax88179_178a.c