Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751664AbbLUMQh (ORCPT ); Mon, 21 Dec 2015 07:16:37 -0500 Received: from unicorn.mansr.com ([81.2.72.234]:53665 "EHLO unicorn.mansr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751304AbbLUMQf convert rfc822-to-8bit (ORCPT ); Mon, 21 Dec 2015 07:16:35 -0500 From: =?iso-8859-1?Q?M=E5ns_Rullg=E5rd?= To: Julian Margetson Cc: Andy Shevchenko , Viresh Kumar , Andy Shevchenko , Tejun Heo , linux-ide@vger.kernel.org, "linux-kernel\@vger.kernel.org" Subject: Re: [PATCH 1/3] ata: sata_dwc_460ex: use "dmas" DT property to find dma channel References: <1450221935-6034-1-git-send-email-mans@mansr.com> <567541EE.9010308@candw.ms> <56758F33.20804@candw.ms> <5675A84F.2070208@candw.ms> <5675BB2F.6060107@candw.ms> <5675C452.2080206@candw.ms> <5676E906.1060603@candw.ms> <5677D447.40906@candw.ms> Date: Mon, 21 Dec 2015 12:16:34 +0000 In-Reply-To: <5677D447.40906@candw.ms> (Julian Margetson's message of "Mon, 21 Dec 2015 06:28:23 -0400") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.5 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3616 Lines: 91 Julian Margetson writes: > On 12/21/2015 4:40 AM, Andy Shevchenko wrote: >> +Viresh >> >> On Mon, Dec 21, 2015 at 2:58 AM, M?ns Rullg?rd wrote: >>> Andy Shevchenko writes: >>> >>>> On Sun, Dec 20, 2015 at 8:49 PM, M?ns Rullg?rd wrote: >>>>> Julian Margetson writes: >>>>>> On 12/20/2015 1:11 PM, M?ns Rullg?rd wrote: >>>>>>> Julian Margetson writes: >>>>>> [ 48.769671] ata3.00: failed command: READ FPDMA QUEUED >>>>> Well, that didn't help. I still think it's part of the problem, but >>>>> something else must be wrong as well. The various Master Select fields >>>>> look like a good place to start. >>>> Master number (which is here would be either 1 or 0) should not affect >>>> as long as they are connected to the same AHB bus (I would be >>>> surprised if they are not). >>> I think they are not. The relevant part of the block diagram for the >>> 460EX looks something like this: >>> >>> +-----+ >>> | CPU | >>> +-----+ >>> | >>> +---------------+ >>> | BUS | >>> +---------------+ >>> | | >>> +-----+ +-----+ >>> | DMA | | RAM | >>> +-----+ +-----+ >>> | >>> +------+ >>> | SATA | >>> +------+ >>> >>> The DMA-SATA link is private and ignores the address, which is the only >>> reason the driver can possibly work (it's programming a CPU virtual >>> address there). >> If you look at the original code the SMS and DMS are programmed >> statically independent on DMA direction, so LLP is programmed always >> to master 1. I don't think your scheme is reflecting this right. I >> could imagine two AHB buses, one of them connects CPU, SATA and RAM, >> and the other CPU and DMA. >> >> In any case on all Intel SoCs and AVR32, and as far as I can tell on >> Spear13xx (Viresh?) there is not a case, that's why I hardly imagine >> that the problem is in master numbers by themselves. >> >>>>> Also, the manual says the LLP_SRC_EN >>>>> and LLP_DST_EN flags should be cleared on the last in a chain of blocks. >>>>> The old sata_dwc driver does this whereas dw_dma does not. >>>> Easy to fix, however I can't get how it might affect. >>> From the Atmel doc: >>> >>> In Table 17-1 on page 185, all other combinations of LLPx.LOC = 0, >>> CTLx.LLP_S_EN, CFGx.RELOAD_SR, CTLx.LLP_D_EN, and CFGx.RELOAD_DS are >>> illegal, and causes indeterminate or erroneous behavior. >> I will check Synospys documentation later on. >> >>> Most likely nothing happens, but I think it ought to be fixed. In fact, >>> I have a patch already. >> Good. Send with Fixes tag if it's upstream ready. >> >>> Come to think of it, I have an AVR32 dev somewhere. Maybe I should dust >>> it off. >> I have ATNGW100. >> >> P.S. Anyway we have to ask Julian to try the kernel with >> 8b3444852a2b58129 reverted. >> > git revert 8b3444852a2b58129 > error: could not revert 8b34448... sata_dwc_460ex: move to generic DMA driver > hint: after resolving the conflicts, mark the corrected paths > hint: with 'git add ' or 'git rm ' > hint: and commit the result with 'git commit' Yeah, that won't work since there are numerous changes afterward. Just revert the entire file back to 4.0 like this: $ git checkout v4.0 drivers/ata/sata_dwc_460ex.c -- M?ns Rullg?rd -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/