Messages in this thread | | | From | David Laight <> | Subject | RE: [PATCH] x86: only use ERMS for user copies for larger sizes | Date | Mon, 26 Nov 2018 10:26:08 +0000 |
| |
From: Linus Torvalds > Sent: 23 November 2018 16:36 ... > End result: we *used* to do this right. For the last eight years our > "memcpy_{to,from}io()" has been entirely broken, and apparently even > the people who noticed oddities like David, never reported it as > breakage but instead just worked around it in drivers.
I've mentioned it several times...
Probably no one else noticed lots of single byte transfers while testing a TLP monitor he was writing for an FPGA :-) They are far too expensive to buy, and would never be connected to the right system at the right time - so we (I) wrote one.
Unfortunately we don't really get to see what happens when the link comes up (or rather doesn't come up). We only get the LTSSM state transitions.
David
- Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
| |