lkml.org 
[lkml]   [2007]   [Mar]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] libata: warn if speed limited due to 40-wire cable (v2)
Bill Davidsen wrote:

>Stephen Clark wrote:
>
>
>>Bill Davidsen wrote:
>>
>>
>>
>>>Alan Cox wrote:
>>>
>>>
>>>
>>>
>>>>>it seems broken to manipulate xfer_mask after returning from the
>>>>>driver's ->mode_filter hook.
>>>>>
>>>>>this patch is more than just a speed-limited warning printk, afaics
>>>>>
>>>>>
>>>>>
>>>>I actually suggested that order because the only way the printk can be
>>>>done correctly is for it to be the very last test made. Since the mode
>>>>filter is not told what mode will be used but just subtracts modes that
>>>>are not allowed this should be safe.
>>>>
>>>>
>>>>
>>>Far better to have a drive which works slowly than one which works
>>>unreliably.
>>>
>>>
>>>
>>>
>>>
>>That would be true if the 40 wire detection was 100% accurate!
>>
>>
>The statement is completely correct, even though the detection may not
>be. ;-)
>
>With the current set(s) of patches to do better detection, cable
>evaluation should be better. But even if not, a slow system is more
>useful than one which doesn't work, crashes because of swap i/o errors, etc.
>
>
>
I have had problems with cable detection on my previous laptop and my
current laptop. It almost made
my systems unusable. On my current laptop I was getting a thruput of a
little over 1 mbps instead
of the 44 mbps I get with udma set to the correct value. It took hours
to upgrade my laptop from
fc5 to fc6 because of this mis detection.

--

"They that give up essential liberty to obtain temporary safety,
deserve neither liberty nor safety." (Ben Franklin)

"The course of history shows that as a government grows, liberty
decreases." (Thomas Jefferson)



-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-03-05 00:53    [W:0.054 / U:2.532 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site