From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylylov Subject: ide-dma: fix ide_build_dmatable() for TRM290 Date: Sun, 28 Sep 2008 22:41:26 +0400 Message-ID: <200809282241.26289.sshtylyov@ru.mvista.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from rtsoft3.corbina.net ([85.21.88.6]:52662 "EHLO buildserver.ru.mvista.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1752096AbYI1Ska (ORCPT ); Sun, 28 Sep 2008 14:40:30 -0400 Content-Disposition: inline Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: bzolnier@gmail.com Cc: linux-ide@vger.kernel.org Apparently, 'xcount' being 0 does not mean 0 bytes for TRM290; it means 4 bytes, judging from the code immediately preceding this check. So, we must never try to "split" the PRD for TRM290. This is probably never hit anyway -- with the DMA buffers aligned to at least 512 bytes and ATAPI DMA not being used for non block I/O commands... Signed-off-by: Sergei Shtylyov --- The patch is against the recent Linus' tree. drivers/ide/ide-dma.c | 2 +- 1 files changed, 1 insertion(+), 1 deletion(-) Index: linux-2.6/drivers/ide/ide-dma.c =================================================================== --- linux-2.6.orig/drivers/ide/ide-dma.c +++ linux-2.6/drivers/ide/ide-dma.c @@ -211,7 +211,7 @@ int ide_build_dmatable (ide_drive_t *dri xcount = bcount & 0xffff; if (is_trm290) xcount = ((xcount >> 2) - 1) << 16; - if (xcount == 0x0000) { + else if (xcount == 0x0000) { /* * Most chipsets correctly interpret a length of 0x0000 as 64KB, * but at least one (e.g. CS5530) misinterprets it as zero (!).