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From: Jim Nelson <james4765@verizon.net>
To: Jan Dittmer <jdittmer@ppp0.net>
Cc: kernel-janitors@lists.osdl.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] lcd: replace cli()/sti() with spin_lock_irqsave()/spin_unlock_irqrestore()
Date: Fri, 17 Dec 2004 22:02:16 -0500	[thread overview]
Message-ID: <41C39DB8.6050403@verizon.net> (raw)
In-Reply-To: <41C380D0.9020001@ppp0.net>

Jan Dittmer wrote:
> James Nelson wrote:
> 
>>Remove the cli()/sti() calls in drivers/char/lcd.c
> 
> 
> Why is this cli() there in the first place? ioctl is already
> called under lock_kernel.
> 
> 

First - a warning.  Newbie on the loose, running around, asking for a whack with 
the cluebat.

I had seen other drivers that had cli()/sti() calls in the ioctl functions.  So, 
that is wrong?  Should all of those cli()/sti() calls be removed?

Just to site things properly in my mind, was it always the case that ioctl is 
called under lock_kernel, or is this a relatively recent (2.3+) development?  Some 
of the *really* abandoned drivers haven't been touched in at least that long.

>>Signed-off-by: James Nelson <james4765@gmail.com>
>>
>>diff -urN --exclude='*~' linux-2.6.10-rc3-mm1-original/drivers/char/lcd.c linux-2.6.10-rc3-mm1/drivers/char/lcd.c
>>--- linux-2.6.10-rc3-mm1-original/drivers/char/lcd.c	2004-12-03 16:53:42.000000000 -0500
>>+++ linux-2.6.10-rc3-mm1/drivers/char/lcd.c	2004-12-17 18:57:10.760197439 -0500
>>@@ -33,6 +33,8 @@
>> 
>> #include "lcd.h"
>> 
>>+static spinlock_t lcd_lock = SPIN_LOCK_UNLOCKED;
>>+
>> static int lcd_ioctl(struct inode *inode, struct file *file,
>> 		     unsigned int cmd, unsigned long arg);
>> 
>>@@ -464,14 +466,13 @@
>> 			}
>> 
>> 			printk("Churning and Burning -");
>>-			save_flags(flags);
>> 			for (i = 0; i < FLASH_SIZE; i = i + 128) {
>> 
>> 				if (copy_from_user
>> 				    (rom, display.RomImage + i, 128))
>> 					return -EFAULT;
> 
> 
> The driver is leaking memory, rom is not freed in this case.

Erm.  Didn't notice that.

> 
> Jan
> -
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> 


  reply	other threads:[~2004-12-18  3:03 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-12-17 23:59 [PATCH] lcd: replace cli()/sti() with spin_lock_irqsave()/spin_unlock_irqrestore() James Nelson
2004-12-18  0:58 ` Jan Dittmer
2004-12-18  3:02   ` Jim Nelson [this message]
2004-12-18  4:40     ` [KJ] " Matthew Wilcox
2004-12-18  4:15 ` [KJ] " Matthew Wilcox

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