From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Subject: Re: libata pata_pdc2027x success on sparc64 Date: Thu, 27 Jul 2006 20:35:08 +0400 Message-ID: <44C8EB3C.4080404@ru.mvista.com> References: <200607172358.k6HNwYhF002052@harpo.it.uu.se> <44BD2370.8090506@ru.mvista.com> <44C841B5.40806@tw.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from gateway-1237.mvista.com ([63.81.120.155]:10656 "EHLO imap.sh.mvista.com") by vger.kernel.org with ESMTP id S1751645AbWG0QgX (ORCPT ); Thu, 27 Jul 2006 12:36:23 -0400 In-Reply-To: <44C841B5.40806@tw.ibm.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: albertl@mail.com Cc: Mikael Pettersson , linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org, alan@redhat.com, Unicorn Chang , Doug Maxey Hello. Albert Lee wrote: >>>In contrast, the old IDE pdc202xx_new driver had lots >>>of problems with CRC errors causing it to disable DMA. >> Hm, from my experience it usually falls back to UltraDMA/44 and then >>the thing startrt working... >>>I wasn't able to manually tune it above udma3 without >>>getting more errors. This isn't sparc64-specific: I've >>>had similar negative experience with the old IDE Promise >>>drivers in a PowerMac. >> This happens because the "old" driver misses the PLL calibration code. >> You may want to try these Albert's patches: >>http://marc.theaimsgroup.com/?t=110992452800002&r=1&w=2 >>http://marc.theaimsgroup.com/?t=110992471500002&r=1&w=2 >>http://marc.theaimsgroup.com/?t=110992490100002&r=1&w=2 >>http://marc.theaimsgroup.com/?t=111019238400003&r=1&w=2 >> It looks like they were never considered for accepting into the kernel >>while they succesfully solve this issue. Maybe Albert could try pushing >>them into -mm tree once more? > The libata version has three improvements compared to the IDE version. > 1. The PLL calibration patches in the above URLs (for IDE) > still need more improvement as done in the pdc_read_counter() > of the libata version. Indeed. When backporting your patches to 2.6.10, I've added alike function, so can generate an extra patch against those. > 2. The Promise 2027x adapters check the "set features - xfer mode" > and set the timing register automatically. However, the automatically > set values are not correct under 133MHz. Libata has a hook > pdc2027x_post_set_mode() to set the values back by software. You probably forgot -- the last mentioned patch was all about it. :-) > 3. ATAPI DMA is supported (please see pdc2027x_check_atapi_dma()). > Maybe we also need to add this to the IDE version. Wouldn't hurt. :-) > Currently I have no time to update the IDE pdc202xx_new driver. I'll probably take this on then, starting with pushing this half-buried stuff into -mm tree. > Also as Alan said, we have no maintainer for the IDE layer at this time. > So, if ok, please try to use the libata-based driver. WBR, Sergei