From: Domen Puncer <domen@coderock.org>
To: James Nelson <james4765@verizon.net>
Cc: kernel-janitors@lists.osdl.org, linux-kernel@vger.kernel.org,
akpm@osdl.org
Subject: [KJ] Re: lcd: fix memory leak, code cleanup
Date: Tue, 21 Dec 2004 12:06:07 +0000 [thread overview]
Message-ID: <20041221120607.GA30293@nd47.coderock.org> (raw)
In-Reply-To: <20041221015120.29110.98832.48706@localhost.localdomain>
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On 20/12/04 19:50 -0600, James Nelson wrote:
> This patch addresses the following issues:
>
> Fix log-spamming and cryptic error messages, and add KERN_ constants.
> Convert some ints to unsigned ints.
> Add checks for CAP_SYS_ADMIN for FLASH_Burn and FLASH_Erase ioctls.
> Identify use of global variable.
> Fix memory leak in FLASH_Burn ioctl.
> Fix error return codes in lcd_ioctl().
> Move variable "index" in lcd_ioctl() to smaller scope to reduce memory usage.
> Convert cli()/sti() to spin_lock_irqsave()/spin_unlock_irqrestore().
> Fix legibility issues in FLASH_Burn ioctl.
>
> - cli();
> + spin_lock_irqsave(&lcd_lock, flags);
> for (index = 0; index < (128); index++) {
>
> WRITE_FLASH(kFlash_Addr1,
> @@ -480,32 +485,30 @@
> kFlash_Data2);
> WRITE_FLASH(kFlash_Addr1,
> kFlash_Prog);
> - *((volatile unsigned char *)
> - burn_addr) =
> - (volatile unsigned char) rom[index];
> -
> - while ((!dqpoll
> - (burn_addr,
> - (volatile unsigned char)
> - rom[index]))
> - && (!timeout(burn_addr))) {
> - }
> + *((volatile unsigned char *)burn_addr) =
> + (volatile unsigned char) rom[index];
> +
> + while ((!dqpoll (burn_addr,
> + (volatile unsigned char)
> + rom[index])) &&
> + (!timeout(burn_addr))) { }
> burn_addr++;
> }
> - restore_flags(flags);
> - if (*
> - ((volatile unsigned char *) (burn_addr
> - - 1)) ==
> - (volatile unsigned char) rom[index -
> - 1]) {
> + spin_unlock_irqrestore(&lcd_lock, flags);
Although this will work, i think local_irq_{disable,enable} is the right
solution (we don't protect any data, just make sure timings are right).
For making it SMP safe, easiest/sane solution seems semaphore in
lcd_dev, which is down_interruptible(), at beginning of read, write
and ioctl.
Comments?
Domen
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WARNING: multiple messages have this Message-ID (diff)
From: Domen Puncer <domen@coderock.org>
To: James Nelson <james4765@verizon.net>
Cc: kernel-janitors@lists.osdl.org, linux-kernel@vger.kernel.org,
akpm@osdl.org
Subject: Re: lcd: fix memory leak, code cleanup
Date: Tue, 21 Dec 2004 13:06:07 +0100 [thread overview]
Message-ID: <20041221120607.GA30293@nd47.coderock.org> (raw)
In-Reply-To: <20041221015120.29110.98832.48706@localhost.localdomain>
On 20/12/04 19:50 -0600, James Nelson wrote:
> This patch addresses the following issues:
>
> Fix log-spamming and cryptic error messages, and add KERN_ constants.
> Convert some ints to unsigned ints.
> Add checks for CAP_SYS_ADMIN for FLASH_Burn and FLASH_Erase ioctls.
> Identify use of global variable.
> Fix memory leak in FLASH_Burn ioctl.
> Fix error return codes in lcd_ioctl().
> Move variable "index" in lcd_ioctl() to smaller scope to reduce memory usage.
> Convert cli()/sti() to spin_lock_irqsave()/spin_unlock_irqrestore().
> Fix legibility issues in FLASH_Burn ioctl.
>
> - cli();
> + spin_lock_irqsave(&lcd_lock, flags);
> for (index = 0; index < (128); index++) {
>
> WRITE_FLASH(kFlash_Addr1,
> @@ -480,32 +485,30 @@
> kFlash_Data2);
> WRITE_FLASH(kFlash_Addr1,
> kFlash_Prog);
> - *((volatile unsigned char *)
> - burn_addr) =
> - (volatile unsigned char) rom[index];
> -
> - while ((!dqpoll
> - (burn_addr,
> - (volatile unsigned char)
> - rom[index]))
> - && (!timeout(burn_addr))) {
> - }
> + *((volatile unsigned char *)burn_addr) =
> + (volatile unsigned char) rom[index];
> +
> + while ((!dqpoll (burn_addr,
> + (volatile unsigned char)
> + rom[index])) &&
> + (!timeout(burn_addr))) { }
> burn_addr++;
> }
> - restore_flags(flags);
> - if (*
> - ((volatile unsigned char *) (burn_addr
> - - 1)) ==
> - (volatile unsigned char) rom[index -
> - 1]) {
> + spin_unlock_irqrestore(&lcd_lock, flags);
Although this will work, i think local_irq_{disable,enable} is the right
solution (we don't protect any data, just make sure timings are right).
For making it SMP safe, easiest/sane solution seems semaphore in
lcd_dev, which is down_interruptible(), at beginning of read, write
and ioctl.
Comments?
Domen
next prev parent reply other threads:[~2004-12-21 12:06 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-12-21 1:50 [KJ] [PATCH] lcd: fix memory leak, code cleanup James Nelson
2004-12-21 1:50 ` James Nelson
2004-12-21 8:15 ` [KJ] " walter harms
2004-12-21 12:06 ` Domen Puncer [this message]
2004-12-21 12:06 ` Domen Puncer
2004-12-22 3:45 ` [KJ] " Jim Nelson
2004-12-22 3:45 ` Jim Nelson
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