From: Daniel Drake <dsd@gentoo.org>
To: nick.cheng@areca.com.tw
Cc: 'James Bottomley' <James.Bottomley@HansenPartnership.com>,
linux-scsi@vger.kernel.org
Subject: Re: Patch added to scsi-rc-fixes-2.6: [SCSI] arcmsr: fix message allocation
Date: Mon, 25 Feb 2008 10:14:30 +0000 [thread overview]
Message-ID: <47C29506.4000609@gentoo.org> (raw)
In-Reply-To: <001401c87753$3edf4670$8800a8c0@Nick>
nickcheng wrote:
> Hi,
> I definitely agree it is in atomic context but why is the memory not for
> DMA?
> Would you please show me why?
It would probably be easier if you could explain where you believe the
memory IS used for DMA :)
Anyway, looking at ARCMSR_MESSAGE_READ_RQBUFFER
current code does this:
ver_addr = kmalloc(1032, GFP_ATOMIC);
Here are the cases when that buffer is used:
checking for successful malloc: not DMA
if (!ver_addr) {
copying the address: not DMA
ptmpQbuffer = ver_addr;
memcpying 1 byte into the buffer: not DMA
memcpy(ptmpQbuffer, pQbuffer, 1);
incrementing address: not DMA
ptmpQbuffer++;
memcpying from the buffer: not DMA
memcpy(pcmdmessagefld->messagedatabuffer, ver_addr, allxfer_len);
freeing the buffer: not DMA
kfree(ver_addr);
Daniel
next parent reply other threads:[~2008-02-25 10:12 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <001401c87753$3edf4670$8800a8c0@Nick>
2008-02-25 10:14 ` Daniel Drake [this message]
2008-02-25 10:47 ` Patch added to scsi-rc-fixes-2.6: [SCSI] arcmsr: fix message allocation nickcheng
2008-02-25 14:38 ` James Bottomley
2008-02-26 4:29 ` Patch added to scsi-rc-fixes-2.6: [SCSI] arcmsr: fix messageallocation nickcheng
2008-02-26 16:14 ` James Bottomley
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