From mboxrd@z Thu Jan 1 00:00:00 1970 From: Suravee Suthikulpanit Subject: Re: [PATCH 1/1] ata: Check and set 64-bit DMA mask for platform AHCI driver Date: Thu, 12 Jun 2014 01:22:29 -0500 Message-ID: <53994725.5000001@amd.com> References: <1400866510-3130-1-git-send-email-suravee.suthikulpanit@amd.com> <20140603175827.GH26210@htj.dyndns.org> <5391E812.1060009@amd.com> <1666501.UPn96gHtAf@amdc1032> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-bn1blp0185.outbound.protection.outlook.com ([207.46.163.185]:34889 "EHLO na01-bn1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752158AbaFLGWj (ORCPT ); Thu, 12 Jun 2014 02:22:39 -0400 In-Reply-To: <1666501.UPn96gHtAf@amdc1032> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Bartlomiej Zolnierkiewicz Cc: Tejun Heo , Hans de Goede , linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org, lho@apm.com, tphan@apm.com, stripathi@apm.com On 06/11/2014 04:41 AM, Bartlomiej Zolnierkiewicz wrote: >>> On Fri, May 23, 2014 at 12:35:10PM -0500,suravee.suthikulpanit@amd.com wrote: >>>> > >>From: Suravee Suthikulpanit >>>> > >> >>>> > >>The current platform AHCI drier does not set the dma_mask correctly >>>> > >>for 64-bit DMA capable AHCI controller. This patch checks the AHCI >>>> > >>capability bit and set the dma_mask and coherent_dma_mask accordingly. >>>> > >> >>>> > >>Signed-off-by: Suravee Suthikulpanit >>>> > >>--- >>>> > >> drivers/ata/libahci_platform.c | 9 +++++++++ >>>> > >> 1 file changed, 9 insertions(+) >>>> > >> >>>> > >>diff --git a/drivers/ata/libahci_platform.c b/drivers/ata/libahci_platform.c >>>> > >>index 7cb3a85..85049ef 100644 >>>> > >>--- a/drivers/ata/libahci_platform.c >>>> > >>+++ b/drivers/ata/libahci_platform.c >>>> > >>@@ -368,6 +368,15 @@ int ahci_platform_init_host(struct platform_device *pdev, >>>> > >> ahci_init_controller(host); >>>> > >> ahci_print_info(host, "platform"); >>>> > >> >>>> > >>+ if (hpriv->cap & HOST_CAP_64) { >>>> > >>+ if (!dev->dma_mask) > What configuration is the above dev->dma_mask checking supposed to handle? > Is it really needed? If not the current dma_set_mask_and_coherent() call > can be replaced by dma_coerce_mask_and_coherent() one. I was just trying to be safe and not always assuming that dev->dma_mask is pointing to the dev->coherent_dma_mask. If you think this is not necessary, I can remove this. > >>>> > >>+ dev->dma_mask = &dev->coherent_dma_mask; >>>> > >>+ >>>> > >>+ rc = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64)); >>>> > >>+ if (rc) >>>> > >>+ return rc; > Shouldn't we try to set DMA masks to 32-bit ones on error (like it is done > in ahci_configure_dma_masks()) instead of failing the initialization? I can also add the additional logic to try for 32-bit. > >>>> > >>+ } >>>> > >>+ >>>> > >> return ata_host_activate(host, irq, ahci_interrupt, IRQF_SHARED, >>>> > >> &ahci_platform_sht); >>>> > >> } >>>> > >>-- >>>> > >>1.9.0 > BTW It seems that after DMA masks handling is fixed in the generic AHCI > platform code the driver specific code in ahci_xgene.c can be removed. I am including Loc Ho, Tuan Phan, and Suman Tripathi to help verifying if code could be removed. If so, I'll send out the change in V2. Suravee > > Best regards, > -- > Bartlomiej Zolnierkiewicz > Samsung R&D Institute Poland > Samsung Electronics >