public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Jiri Slaby <jirislaby@gmail.com>
To: Ingo Korb <ml@akana.de>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	linux-kernel@vger.kernel.org, Alan Cox <alan@lxorguk.ukuu.org.uk>
Subject: Re: [PATCH 1/1] Char: istallion, init+locking fixes
Date: Tue, 19 Jun 2007 09:42:08 +0200	[thread overview]
Message-ID: <467788D0.4060802@gmail.com> (raw)
In-Reply-To: <uir9l9e1j.fsf@dragon.akana.de>

Ingo Korb napsal(a):
> Move brdp->iosize assignment in stli_initecp up a few lines to stop the
> driver from requesting an I/O region of length 0.
> 
> Remove spin_lock_irqsave/spin_unlock_irqrestore from __stli_sendcmd as
> all users of that function take the lock already.
> 
> Signed-off-by: Ingo Korb <ml@akana.de>
> ---
> One thing I dislike about this driver: It polls its cards every jiffy to
> look for new data. The cards are able to use interrupts (some of the
> drivers for other OSes use them), but as far as I know there is no open
> documentation. Unfortunately the DOS driver (probably easiest to
> analyze) also uses polling. =(
> 
> 
> diff --git a/drivers/char/istallion.c b/drivers/char/istallion.c
> index 7b279d1..0bc1c37 100644
> --- a/drivers/char/istallion.c
> +++ b/drivers/char/istallion.c
> @@ -2168,8 +2168,6 @@ static void __stli_sendcmd(struct stlibrd *brdp, struct stliport *portp, unsigne
>  	unsigned char __iomem *bits;
>  	unsigned long flags;

Remove the flags and you will see the bug, you introduced ;).

> -	spin_lock_irqsave(&brd_lock, flags);
> -
>  	if (test_bit(ST_CMDING, &portp->state)) {
>  		printk(KERN_ERR "STALLION: command already busy, cmd=%x!\n",
>  				(int) cmd);
> @@ -2194,7 +2192,6 @@ static void __stli_sendcmd(struct stlibrd *brdp, struct stliport *portp, unsigne
>  	writeb(readb(bits) | portp->portbit, bits);
>  	set_bit(ST_CMDING, &portp->state);
>  	EBRDDISABLE(brdp);
> -	spin_unlock_irqrestore(&brd_lock, flags);
>  }


regards,
-- 
http://www.fi.muni.cz/~xslaby/            Jiri Slaby
faculty of informatics, masaryk university, brno, cz
e-mail: jirislaby gmail com, gpg pubkey fingerprint:
B674 9967 0407 CE62 ACC8  22A0 32CC 55C3 39D4 7A7E

  reply	other threads:[~2007-06-19  7:42 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-06-18 20:57 [PATCH 1/1] Char: istallion, init+locking fixes Ingo Korb
2007-06-19  7:42 ` Jiri Slaby [this message]
2007-06-19 14:32   ` Ingo Korb
2007-06-19 14:39   ` [PATCH 1/1] Char: istallion, init+locking fixes (try 2) Ingo Korb

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=467788D0.4060802@gmail.com \
    --to=jirislaby@gmail.com \
    --cc=akpm@linux-foundation.org \
    --cc=alan@lxorguk.ukuu.org.uk \
    --cc=linux-kernel@vger.kernel.org \
    --cc=ml@akana.de \
    /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