From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jean Delvare Subject: [PATCH] IDE: Silent compiler warning in ide_pio_bytes() Date: Mon, 22 Jun 2009 21:10:52 +0200 Message-ID: <20090622211052.45b3cfc5@hyperion.delvare> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Received: from zone0.gcu-squad.org ([212.85.147.21]:5991 "EHLO services.gcu-squad.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751631AbZFVTLB (ORCPT ); Mon, 22 Jun 2009 15:11:01 -0400 Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Bartlomiej Zolnierkiewicz , linux-ide@vger.kernel.org PageHighMem() isn't cheap so avoid calling it several times on the same page. I had the hope that this would silent the following compilation warning: drivers/ide/ide-taskfile.c: In function 'ide_pio_bytes': drivers/ide/ide-taskfile.c:229: warning: 'flags' may be used uninitialized in this function which is a false positive, but it did not. So let's just initialize the flags and be done with it, so that other developers don't waste their time looking at it. Signed-off-by: Jean Delvare Cc: Bartlomiej Zolnierkiewicz --- drivers/ide/ide-taskfile.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) --- linux-2.6.31-pre.orig/drivers/ide/ide-taskfile.c 2009-06-21 09:37:02.000000000 +0200 +++ linux-2.6.31-pre/drivers/ide/ide-taskfile.c 2009-06-21 12:18:47.000000000 +0200 @@ -226,7 +226,7 @@ void ide_pio_bytes(ide_drive_t *drive, s struct scatterlist *sg = hwif->sg_table; struct scatterlist *cursg = cmd->cursg; struct page *page; - unsigned long flags; + unsigned long flags = 0; /* Silent compiler warning */ unsigned int offset; u8 *buf; @@ -236,6 +236,7 @@ void ide_pio_bytes(ide_drive_t *drive, s while (len) { unsigned nr_bytes = min(len, cursg->length - cmd->cursg_ofs); + int page_is_high; if (nr_bytes > PAGE_SIZE) nr_bytes = PAGE_SIZE; @@ -247,7 +248,8 @@ void ide_pio_bytes(ide_drive_t *drive, s page = nth_page(page, (offset >> PAGE_SHIFT)); offset %= PAGE_SIZE; - if (PageHighMem(page)) + page_is_high = PageHighMem(page); + if (page_is_high) local_irq_save(flags); buf = kmap_atomic(page, KM_BIO_SRC_IRQ) + offset; @@ -268,7 +270,7 @@ void ide_pio_bytes(ide_drive_t *drive, s kunmap_atomic(buf, KM_BIO_SRC_IRQ); - if (PageHighMem(page)) + if (page_is_high) local_irq_restore(flags); len -= nr_bytes; -- Jean Delvare