From mboxrd@z Thu Jan 1 00:00:00 1970 From: "erich" Subject: Re: Areca RAID driver remaining items? Date: Fri, 24 Feb 2006 11:18:17 +0800 Message-ID: <006101c638f0$f6583440$b100a8c0@erich2003> Mime-Version: 1.0 Content-Type: text/plain; format=flowed; charset="big5"; reply-type=response Content-Transfer-Encoding: 7bit Return-path: Sender: linux-kernel-owner@vger.kernel.org To: erich Cc: "\"Christoph Hellwig\"" , linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, billion.wu@areca.com.tw, alan@lxorguk.ukuu.org.uk, akpm@osdl.org, oliver@neukum.org List-Id: linux-scsi@vger.kernel.org Dear Arjan van de Ven, I had misconstruction with >> [Exception is that you can say that you are ok with a bigger mask for >> this type of memory, but just don't do that if you're not] it should be "pci_set_consistent_dma_mask(pdev, DMA_32BIT_MASK)." Best Regards Erich Chen ----- Original Message ----- From: "erich" To: "Arjan van de Ven" Cc: """"Christoph Hellwig"""" ; ; ; ; ; ; Sent: Friday, February 24, 2006 10:08 AM Subject: Re: Areca RAID driver remaining items? > Dear Arjan van de Ven, > > I would keep dma_alloc_coherent usage. > >> [Exception is that you can say that you are ok with a bigger mask for >> this type of memory, but just don't do that if you're not] > > Should I remove "pci_set_dma_mask(pci_device, DMA_64BIT_MASK)" for this > case? > > Best Regards > Erich Chen > > ----- Original Message ----- > From: "Arjan van de Ven" > To: "erich" > Cc: """Christoph Hellwig""" ; > ; ; > ; ; ; > > Sent: Thursday, February 23, 2006 8:07 PM > Subject: Re: Areca RAID driver remaining items? > > >> On Thu, 2006-02-23 at 19:51 +0800, erich wrote: >>> If Linux can not assurent the contingous memory space allocating of >>> "dma_alloc_coherent" . >> >> coherent memory is guaranteed to be in the "lower" 32 bit of memory! >> So that is good news, I think you are just fine. >> >> [Exception is that you can say that you are ok with a bigger mask for >> this type of memory, but just don't do that if you're not] >> >> >>> When arcmsr get a physical ccb address from areca's firmware. >>> Does linux has any functions for converting of "bus to virtual" ? >> >> not without using pools. You would have to search the list of memory you >> gave it to find that out. >> >> (USB has a similar problem, afaik they solved it with pools) >> >> >