linux-mtd.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: Richard Weinberger <richard.weinberger@gmail.com>
To: Kamal Dasu <kdasu.kdev@gmail.com>
Cc: Boris Brezillon <bbrezillon@kernel.org>,
	Richard Weinberger <richard@nod.at>,
	LKML <linux-kernel@vger.kernel.org>,
	Marek Vasut <marek.vasut@gmail.com>,
	bcm-kernel-feedback-list@broadcom.com,
	Miquel Raynal <miquel.raynal@bootlin.com>,
	linux-mtd@lists.infradead.org,
	Brian Norris <computersforpeace@gmail.com>,
	David Woodhouse <dwmw2@infradead.org>
Subject: Re: [PATCH] mtd: nand: raw: brcmnand: When oops in progress use pio and interrupt polling
Date: Mon, 6 May 2019 18:01:11 +0200	[thread overview]
Message-ID: <CAFLxGvy7B2K2AX0nSe549QF-gDMZcc5F4X0Y+yzRrnYfL9svEw@mail.gmail.com> (raw)
In-Reply-To: <1556733121-20133-1-git-send-email-kdasu.kdev@gmail.com>

On Wed, May 1, 2019 at 7:52 PM Kamal Dasu <kdasu.kdev@gmail.com> wrote:
>
> If mtd_oops is in progress switch to polling for nand command completion
> interrupts and use PIO mode wihtout DMA so that the mtd_oops buffer can
> be completely written in the assinged nand partition. This is needed in
> cases where the panic does not happen on cpu0 and there is only one online
> CPU and the panic is not on cpu0.

This optimization is highly specific to your hardware and AFAIK cannot
be applied
in general to brcmnand.

So the problem you see is that depending on the oops you can no longer use dma
or interrupts in the driver?

How about adding a new flag to panic_nand_write() which tells the nand
driver that
this is a panic write?
That way you can fall back to pio and polling mode without checking cpu numbers
and oops_in_progress.

-- 
Thanks,
//richard

______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/

  parent reply	other threads:[~2019-05-06 16:01 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-01 17:46 [PATCH] mtd: nand: raw: brcmnand: When oops in progress use pio and interrupt polling Kamal Dasu
2019-05-02  8:25 ` Miquel Raynal
2019-05-02 14:09   ` Kamal Dasu
2019-05-06 16:01 ` Richard Weinberger [this message]
2019-05-16 14:47   ` Kamal Dasu

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=CAFLxGvy7B2K2AX0nSe549QF-gDMZcc5F4X0Y+yzRrnYfL9svEw@mail.gmail.com \
    --to=richard.weinberger@gmail.com \
    --cc=bbrezillon@kernel.org \
    --cc=bcm-kernel-feedback-list@broadcom.com \
    --cc=computersforpeace@gmail.com \
    --cc=dwmw2@infradead.org \
    --cc=kdasu.kdev@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mtd@lists.infradead.org \
    --cc=marek.vasut@gmail.com \
    --cc=miquel.raynal@bootlin.com \
    --cc=richard@nod.at \
    /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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).