hi carl-daniel -- sorry for the delay -- things have been pretty busy recently. that patch certainly looks correct. i haven't been able to try it, but i'll probably be doing some reflashing soon...
Acked-by: Paul Fox <[email protected]> paul carl-daniel wrote: > Hi Paul, hi Richard, > > I remember that one of you mentioned occassional verify failures with > flashrom and the FT2232 code. > The good news is that we recently got a report from another user (Jeremy > Buseman) with whom we could track down some of the issues to timing and > to deficiencies in the software/hardware stack. Running flashrom in > non-verbose mode and with a limit of 36 bytes per SPI command (1 opcode, > 3 address, 32 data) gave him 100% reliable results. > I also have a patch pending which allows a specialized test pattern to > be burned, and the results were surprising: Sometimes, the last two > bytes of a 64-byte block are simply missing, then the next 64-byte block > is moved two bytes in the direction of lower addresses, and so on. For > page (256 byte) reads, this could result in up to 8 bytes at the end > being undefined because some or all 64-byte subpages had been trimmed. > Besides that, verbose mode seems to have thrown off the timing enough to > cause read/write errors as well. In theory, that should not happen (and > libftdi/libusb should ensure consistent behaviour), but reality seems a > bit disillusioning. > > If you could review the patch below which adds some error checking to > give at least some indications on where the problems may lie, I'd > appreciate it. It is entirely possible that you won't get additional > warnings from the patch, but I'd like to run it past you because you > seem to be responsible for the largest FT2232 flashrom deployment. If > you think the patch is OK, please respond with > > Acked-by: Your Name <y...@email> > > On 10.11.2009 04:07, Carl-Daniel Hailfinger wrote: > > Pretty much everybody who used the FT2232 SPI driver in flashrom had > > problems with incorrect reads from time to time. > > One reason was that the hardware is pretty timing sensitive even for reads. > > > > The other reason was that the code silently ignored errors. This patch > > doesn't add any error recovery, but it will emit error messages if > > FT2232 communication goes wrong. That allows us to track down errors > > without investing hours in driver debugging. > > > > Jeremy, I'd be very interested in the results of an unmodified flashrom > > with only this patch applied (read is sufficient). In theory, you should > > either get a working read or loads of error messages about > > send_buf/read_buf. If you get no error messages and the image read is > > still wrong, libftdi doesn't tell us about the problem. Oh, and please > > try in verbose and normal mode. Maybe there's a difference. > > > > Signed-off-by: Carl-Daniel Hailfinger <[email protected]> > > > > In case you're not subscribed to the flashrom mailing list, you can > download the patch here: > http://patchwork.coreboot.org/patch/549/raw/ > > Regards, > Carl-Daniel > > -- > Developer quote of the month: > "We are juggling too many chainsaws and flaming arrows and tigers." =--------------------- paul fox, [email protected] (arlington, ma, where it's 55.2 degrees) _______________________________________________ flashrom mailing list [email protected] http://www.flashrom.org/mailman/listinfo/flashrom
