From mboxrd@z Thu Jan  1 00:00:00 1970
From: Mike Christie <michaelc@cs.wisc.edu>
Subject: Re: 2.6.20-rc6: known unfixed regressions (v2) (part 2)
Date: Mon, 29 Jan 2007 21:02:42 -0600
Message-ID: <45BEB552.7060003@cs.wisc.edu>
References: <Pine.LNX.4.64.0701241847360.25027@woody.linux-foundation.org>  <20070127174230.GN6017@stusta.de>  <20070128133344.214070@gmx.net> <1170051963.6454.7.camel@Homer.simpson.net> <Pine.LNX.4.64.0701282247070.3611@woody.linux-foundation.org> <45BE5AF0.3030005@cs.wisc.edu> <Pine.LNX.4.64.0701291250420.3611@woody.linux-foundation.org> <Pine.LNX.4.64.0701291414410.3611@woody.linux-foundation.org> <Pine.LNX.4.64.0701291453230.3611@woody.linux-foundation.org> <Pine.LNX.4.64.0701291532050.3611@woody.linux-foundation.org> <45BE864A.2050907@cs.wisc.edu> <Pine.LNX.4.64.0701291614020.3611@woody.linux-foundation.org> <45BE9774.20105@cs.wisc.edu> <45BE99A4.9080503@cs.wisc.edu> <Pine.LNX.4.64.0701291736550.3611@woody.linux-foundation.org> <45BEB292.7060008@cs.wisc.edu>
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To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>, Uwe Bugla <uwe.bugla@gmx.de>, Adrian Bunk <bunk@stusta.de>, Andrew Morton <akpm@osdl.org>, gd@spherenet.de, alan@lxorguk.ukuu.org.uk, linux-ide@vger.kernel.org, B.Zolnierkiewicz@elka.pw.edu.pl, Jeff Garzik <jgarzik@pobox.com>, Jens Axboe <jens.axboe@oracle.com>, James Bottomley <James.Bottomley@SteelEye.com>, FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>, Boaz Harrosh <bharrosh@panasas.com>

Mike Christie wrote:
> Linus Torvalds wrote:
>> On Mon, 29 Jan 2007, Mike Christie wrote:
>>> Actually, I do not think we did this in 2.6.19. Tomo added a bug when he
>>> ported a patch and mixed up some things so we did something weird for
>>> 2.6.20-rc1.
>> Ah, ok. Warring bugs.  Have you pinpointed the original one? Is it your 
>> original "block: support larger block pc requests" after all? It looks 
>> like yours is the one that did the big changes, with Tomo then fixing some 
>> of the fallout?
> 
> I am not completely convinced this bug is the "block: support larger
> block pc requests" patches fault. If I revert the jiffies_to_msecs usage
> then it works for me. On my system I have
> CONFIG_HZ_250=y
> CONFIG_HZ=250
> 
> With the attached patch, nero finds the cd drives and I can burn disks.
> There is no errors from the ide layer like before.
> 
> 
> ------------------------------------------------------------------------
> 
> diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
> index 2528a0c..aded9a0 100644
> --- a/block/scsi_ioctl.c
> +++ b/block/scsi_ioctl.c
> @@ -271,7 +271,7 @@ static int sg_io(struct file *file, requ
>  
>  	rq->cmd_type = REQ_TYPE_BLOCK_PC;
>  
> -	rq->timeout = jiffies_to_msecs(hdr->timeout);
> +	rq->timeout = (hdr->timeout * HZ) / 1000;
>  	if (!rq->timeout)
>  		rq->timeout = q->sg_timeout;
>  	if (!rq->timeout)

Or if that patch is wrong maybe we want something like what
drivers/scsi/sg.c uses:

ul_timeout = msecs_to_jiffies(srp->header.timeout);
timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;

I do not think we should be doing jiffies_to_msecs though.