From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f66.google.com ([74.125.82.66]:35411 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751177AbeEVKAm (ORCPT ); Tue, 22 May 2018 06:00:42 -0400 From: Marek Vasut Subject: Re: [PATCH][RFC] PCI: rcar: Add bus notifier so we can limit the DMA range To: Arnd Bergmann Cc: linux-pci , Phil Edworthy , Marek Vasut , Geert Uytterhoeven , Simon Horman , Wolfram Sang , Linux-Renesas , Nikita Yushchenko References: <20180521220514.30256-1-marek.vasut+renesas@gmail.com> Message-ID: Date: Tue, 22 May 2018 11:52:21 +0200 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Sender: linux-pci-owner@vger.kernel.org List-ID: On 05/22/2018 10:10 AM, Arnd Bergmann wrote: > On Tue, May 22, 2018 at 12:05 AM, Marek Vasut wrote: >> From: Phil Edworthy >> >> The PCIe DMA controller on RCar Gen2 and earlier is on 32bit bus, >> so limit the DMA range to 32bit. >> >> Signed-off-by: Phil Edworthy >> Signed-off-by: Marek Vasut >> Cc: Arnd Bergmann >> Cc: Geert Uytterhoeven >> Cc: Phil Edworthy >> Cc: Simon Horman >> Cc: Wolfram Sang >> Cc: linux-renesas-soc@vger.kernel.org >> To: linux-pci@vger.kernel.org >> --- >> NOTE: I'm aware of https://patchwork.kernel.org/patch/9495895/ , but the >> discussion seems to have gone way off, so I'm sending this as a >> RFC. Any feedback on how to do this limiting properly would be nice. > > Doing it in the driver is clearly not appropriate, we must do this in > common code. If I remember correctly, it's specifically ARM64 that is > broken here, it incorrectly allows setting a DMA mask to 64 bit > when that is not available. Yep, that's correct. ARM64 with devices mapping tremendous amounts of memory. So did anything change since that discussion references in the NOTE? -- Best regards, Marek Vasut