Re: Bad SCSI performance with 2.6.14 and Fusion-MPT

["Alan D. Brunelle" <Alan.Brunelle@hp.com>]

Michael Renner wrote:

> Alan D. Brunelle wrote:
>
>> I'm seeing what looks to be the same problem (see: U320 SCSI 
>> negotiation problem in Linux 2.6.13 and later implementations on LSI 
>> Logic / Symbios Logic 53c1030 PCI-X Fusion-MPT Dual Ultra320 SCSI 
>> (rev 08)). [[I think I have a patch (perhaps suspect, but it works 
>> for me), if you're interested.]]
>
>
> Yeah, I'd like to see it. Interestingly another box with the same 
> hardware setup and very slightly different .config works fine with 
> 2.6.14.
>
> best regards,
> michael
>
It doesn't surprise me that a different .config or hardware change would 
affect this. If I understand the problem correctly, then it depends upon 
timing - and changing things (hw or sw) could affect the outcome.

The posting by

The following works for me - but as noted previously, it may be suspect 
in general: I'm concerned about the indefinate delay (theoretical).

diff -ur linux-2.6.14.mm2/drivers/message/fusion/mptbase.c 
linux-2.6.14.mm2.adb/drivers/message/fusion/mptbase.c
--- linux-2.6.14.mm2/drivers/message/fusion/mptbase.c   2005-11-17 
09:17:15.000000000 -0500
+++ linux-2.6.14.mm2.adb/drivers/message/fusion/mptbase.c       
2005-11-17 10:11:52.000000000 -0500
@@ -4994,7 +4994,9 @@
        if ((mf = mpt_get_msg_frame(mpt_base_index, ioc)) == NULL) {
                dcprintk((MYIOC_s_WARN_FMT "mpt_config: no msg frames!\n",
                                ioc->name));
-               return -EAGAIN;
+               do {
+                       msleep(25);
+               } while ((mf = mpt_get_msg_frame(mpt_base_index, ioc)) 
== NULL);
        }
        pReq = (Config_t *)mf;
        pReq->Action = pCfg->action;