Re: [PATCH v2] net: stmmac: bug fix to synchronize stmmac_open and stmmac_dvr_probe

[Pavel Machek]

On Tue 2016-12-27 22:42:36, Kweh, Hock Leong wrote:
> From: "Kweh, Hock Leong" <hock.leong.kweh@xxxxxxxxx>
> 
> If kernel module stmmac driver being loaded after OS booted, there is a
> race condition between stmmac_open() and stmmac_mdio_register(), which is
> invoked inside stmmac_dvr_probe(), and the error is showed in dmesg log as
> PHY not found and stmmac_open() failed:
> [  473.919358] stmmaceth 0000:01:00.0 (unnamed net_device) (uninitialized):
>                 stmmac_dvr_probe: warning: cannot get CSR clock
> [  473.919382] stmmaceth 0000:01:00.0: no reset control found
> [  473.919412] stmmac - user ID: 0x10, Synopsys ID: 0x42
> [  473.919429] stmmaceth 0000:01:00.0: DMA HW capability register supported
> [  473.919436] stmmaceth 0000:01:00.0: RX Checksum Offload Engine supported
> [  473.919443] stmmaceth 0000:01:00.0: TX Checksum insertion supported
> [  473.919451] stmmaceth 0000:01:00.0 (unnamed net_device) (uninitialized):
>                 Enable RX Mitigation via HW Watchdog Timer
> [  473.921395] libphy: PHY stmmac-1:00 not found
> [  473.921417] stmmaceth 0000:01:00.0 eth0: Could not attach to PHY
> [  473.921427] stmmaceth 0000:01:00.0 eth0: stmmac_open: Cannot attach to
>                 PHY (error: -19)
> [  473.959710] libphy: stmmac: probed
> [  473.959724] stmmaceth 0000:01:00.0 eth0: PHY ID 01410cc2 at 0 IRQ POLL
>                 (stmmac-1:00) active
> [  473.959728] stmmaceth 0000:01:00.0 eth0: PHY ID 01410cc2 at 1 IRQ POLL
>                 (stmmac-1:01)
> [  473.959731] stmmaceth 0000:01:00.0 eth0: PHY ID 01410cc2 at 2 IRQ POLL
>                 (stmmac-1:02)
> [  473.959734] stmmaceth 0000:01:00.0 eth0: PHY ID 01410cc2 at 3 IRQ POLL
>                 (stmmac-1:03)
> 
> The resolution moved the register_netdev() function call to the end of
> stmmac_dvr_probe() after stmmac_mdio_register().
> 
> Suggested-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
> Signed-off-by: Kweh, Hock Leong <hock.leong.kweh@xxxxxxxxx>

Acked-by: Pavel Machek <pavel@xxxxxx>

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Attachment: signature.asc
Description: Digital signature