From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-out.m-online.net ([212.18.0.9]:39771 "EHLO mail-out.m-online.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758006AbaDBKew (ORCPT ); Wed, 2 Apr 2014 06:34:52 -0400 From: Marek Vasut To: Kishon Vijay Abraham I Subject: Re: [PATCH] PCI: designware: Remove unnecessary RC BAR setting Date: Wed, 2 Apr 2014 12:34:47 +0200 Cc: Mohit KUMAR DCG , Jingoo Han , "'Bjorn Helgaas'" , "linux-pci@vger.kernel.org" , Pratyush ANAND , "'Richard Zhu'" References: <000801cf4d95$64322ef0$2c968cd0$%han@samsung.com> <2CC2A0A4A178534D93D5159BF3BCB66189FEC4809B@EAPEX1MAIL1.st.com> <533BA157.6030004@ti.com> In-Reply-To: <533BA157.6030004@ti.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="us-ascii" Message-Id: <201404021234.48134.marex@denx.de> Sender: linux-pci-owner@vger.kernel.org List-ID: On Wednesday, April 02, 2014 at 07:34:15 AM, Kishon Vijay Abraham I wrote: > On Wednesday 02 April 2014 11:03 AM, Mohit KUMAR DCG wrote: > > Hello Jingoo, > > > >> -----Original Message----- > >> From: Jingoo Han [mailto:jg1.han@samsung.com] > >> Sent: Wednesday, April 02, 2014 10:53 AM > >> To: Mohit KUMAR DCG > >> Cc: 'Bjorn Helgaas'; linux-pci@vger.kernel.org; Pratyush ANAND; 'Marek > >> Vasut'; 'Richard Zhu'; 'Kishon Vijay Abraham I' > >> Subject: Re: [PATCH] PCI: designware: Remove unnecessary RC BAR setting > >> > >> On Wednesday, April 02, 2014 1:57 PM, Mohit KUMAR DCG wrote: > >>> On Tuesday, April 01, 2014 4:00 PM, Jingoo Han wrote: > >>>> According to the spec, the synopsys core does not implement the > >>>> optional BARs such as BAR0/1. This is based on the assumption that > >>>> the RC host probably has registers on some other internal bus and > >>>> has knowledge and setup access to these registers already. > >>>> So, remove unnecessary RC BAR setting. > >>> > >>> - Normally BARs in RC are not used but somehow available in the > >>> design. One possible BAR use can be if RC has some memory connected to > >> > >> the BAR that needs to be accessed through link. > >> > >>> Otherwise we can ignore BARs setup here. > >> > >> Hi Mohit KUMAR DCG, > >> > >> Thank you for your feedback. > >> > >> I want to know whether or not other SoCs such as ST, Freescale, TI > >> support BAR0/BAR1. If no SoC supports BAR0/BAR1, the unnecessary RC BAR > >> setting code should be removed. > > > > - We are not currently using RC's BAR0/1 in any application but no such > > restriction from HW as ST SoCs support BARs in HW design. > > Neither do we in DRA7xx. I suspect that means we should keep the code to make sure the registers are configured correctly, no? Richard, can you comment on MX6 please ? Best regards, Marek Vasut