RE: [PATCH net 1/2] r8152: fix the sw rx checksum is unavailable

From: Hayes Wang
Date: Thu Nov 24 2016 - 08:27:09 EST

Mark Lord [mailto:mlord@xxxxxxxxx]
> Sent: Thursday, November 24, 2016 8:31 PM
> Nope. Guard zones did not fix it, so it's probably not a prefetch issue.
> Oddly, adding a couple of memory barriers to specific places in the driver
> does help, A LOT. Still not 100%, but it did pass 1800 reboot tests over night
> with only three bad rx_desc's reported.
> That's a new record here for the driver using kmalloc'd buffers,
> and put reliability on par with using non-cacheable buffers.
> Any way we look at it though, the chip/driver are simply unreliable,
> and relying upon hardware checksums (which fail due to the driver
> looking at garbage rather than the checksum bits) leads to data corruption.

I don't think the garbage results from our driver or device.
If it is the issue about memory, I think the host driver ought
to deal with it, because it handles the DMA.

Besides, it doesn't seem to occur for all platforms. I have
tested the iperf more than 26 hours, and it still works fine.
I think I would get the same result on x86 or x86_64 platform.

Best Regards,