From: Tejun Heo <tj@kernel.org>
To: Jassi Brar <jassisinghbrar@gmail.com>
Cc: linux-pci@vger.kernel.org, linux-ide@vger.kernel.org, jgarzik@pobox.com
Subject: Re: SIL24: pcie_set_readrq 4096
Date: Thu, 22 Jul 2010 22:42:38 +0200 [thread overview]
Message-ID: <4C48AD3E.1060108@kernel.org> (raw)
In-Reply-To: <AANLkTiltS3zLLSBgv_VNEXpQvEez2PpObhjmbcZxJ2c8@mail.gmail.com>
On 07/22/2010 04:34 PM, Jassi Brar wrote:
> On Thu, Jul 22, 2010 at 10:18 PM, Tejun Heo <tj@kernel.org> wrote:
>> It's been a while since I read pci-e spec but IIUC readrq size and
>> payload size are independent and if readrq is larger than payload size
>> it's supposed to complete in multiple steps. I could be wrong tho.
> AFAIUI readrq size is independent and not greater than the max_payload size.
> Payload size is what max a device can handle and readrq is what a device can
> ask.
> SIL24 does support 4096 and hence can set readrq to that limit, but if the
> payload capacity of the RC is less than 4096, I am not sure if it is supposed to
> work.
Hmm... my impression is that a single read request may be served by
multiple TLPs, so readrq size can go over payload size which limits
the size of payload in a single TLP, but let's wait for someone more
knowledgeable to chime in.
Thanks.
--
tejun
next prev parent reply other threads:[~2010-07-22 20:42 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-07-22 2:47 SIL24: pcie_set_readrq 4096 Jassi Brar
2010-07-22 13:18 ` Tejun Heo
2010-07-22 14:34 ` Jassi Brar
2010-07-22 20:42 ` Tejun Heo [this message]
2010-07-23 5:30 ` Rolf Eike Beer
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4C48AD3E.1060108@kernel.org \
--to=tj@kernel.org \
--cc=jassisinghbrar@gmail.com \
--cc=jgarzik@pobox.com \
--cc=linux-ide@vger.kernel.org \
--cc=linux-pci@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.