From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Subject: Re: [RFC/RFT PATCH 3/5] scsi: Use dma_max_pfn(dev) helper for bounce_limit calculations Date: Sat, 13 Jul 2013 01:55:58 +0400 Message-ID: <51E07B6E.5090900@cogentembedded.com> References: <1373665694-7580-1-git-send-email-santosh.shilimkar@ti.com> <1373665694-7580-4-git-send-email-santosh.shilimkar@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1373665694-7580-4-git-send-email-santosh.shilimkar@ti.com> Sender: linux-kernel-owner@vger.kernel.org To: Santosh Shilimkar Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Russell King , linux-scsi@vger.kernel.org List-Id: linux-scsi@vger.kernel.org Hello. On 07/13/2013 01:48 AM, Santosh Shilimkar wrote: > DMA bounce limit is the maximum direct DMA'able memory beyond which > bounce buffers has to be used to perform dma operations. SCSI driver > relies on dma_mask but its calculation is based on max_*pfn which > don't have uniform meaning across architectures. So make use of > dma_max_pfn() which is expected to return the DMAable maximum pfn > value across architectures. > Cc: Russell King > Cc: linux-scsi@vger.kernel.org > Signed-off-by: Santosh Shilimkar > --- > drivers/scsi/scsi_lib.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c > index 86d5220..e8275fa 100644 > --- a/drivers/scsi/scsi_lib.c > +++ b/drivers/scsi/scsi_lib.c > @@ -1668,7 +1668,7 @@ u64 scsi_calculate_bounce_limit(struct Scsi_Host *shost) > > host_dev = scsi_get_device(shost); > if (host_dev && host_dev->dma_mask) > - bounce_limit = *host_dev->dma_mask; > + bounce_limit = dma_max_pfn(host_dev) << PAGE_SHIFT; You definitely forgot -1 here. WBR, Sergei