From mboxrd@z Thu Jan 1 00:00:00 1970 From: Grant Likely Subject: Re: [PATCH] [V3] uartlite: move from byte accesses to word accesses Date: Wed, 17 Mar 2010 18:01:28 -0600 Message-ID: References: <873097b0-5388-45b1-8483-3ef01bf8351f@SG2EHSMHS005.ehs.local> <1d3f23371003171631x7e854ff6xd4f647b53b2dbe96@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mail-yw0-f201.google.com ([209.85.211.201]:47015 "EHLO mail-yw0-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751375Ab0CRABt convert rfc822-to-8bit (ORCPT ); Wed, 17 Mar 2010 20:01:49 -0400 Received: by ywh39 with SMTP id 39so688664ywh.21 for ; Wed, 17 Mar 2010 17:01:48 -0700 (PDT) In-Reply-To: <1d3f23371003171631x7e854ff6xd4f647b53b2dbe96@mail.gmail.com> Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: John Williams Cc: John Linn , John Linn , linux-serial@vger.kernel.org, jacmet@sunsite.dk, michal.simek@petalogix.com On Wed, Mar 17, 2010 at 5:31 PM, John Williams wrote: > > > On Thu, Mar 18, 2010 at 7:26 AM, Grant Likely > wrote: >> >> On Wed, Mar 17, 2010 at 12:04 PM, John Linn w= rote: >> > >> > >> >> -----Original Message----- >> >> From: John Linn >> >> Sent: Wednesday, March 17, 2010 10:27 AM >> >> To: 'Grant Likely' >> >> Cc: linux-serial@vger.kernel.org; jacmet@sunsite.dk; >> >> michal.simek@petalogix.com; >> >> john.williams@petalogix.com >> >> Subject: RE: [PATCH] [V3] uartlite: move from byte accesses to wo= rd >> >> accesses >> >> >> >> > -----Original Message----- >> >> > From: glikely@secretlab.ca [mailto:glikely@secretlab.ca] On Beh= alf Of >> >> > Grant Likely >> >> > Sent: Wednesday, March 17, 2010 10:21 AM >> >> > To: John Linn >> >> > Cc: linux-serial@vger.kernel.org; jacmet@sunsite.dk; >> >> > michal.simek@petalogix.com; >> >> > john.williams@petalogix.com >> >> > Subject: Re: [PATCH] [V3] uartlite: move from byte accesses to = word >> >> > accesses >> >> > >> >> > On Wed, Mar 17, 2010 at 9:40 AM, John Linn >> >> > wrote: >> >> > > Byte accesses for I/O devices in Xilinx IP is going to be les= s >> >> > > desired in the future such that the driver is being changed t= o >> >> > > use 32 bit accesses. >> >> > > >> >> > > This change facilitates using the uartlite IP over a PCIe bus >> >> > > which only allows 32 bit accesses. >> >> > > >> >> > > Signed-off-by: John Linn >> >> > > >> >> > > --- >> >> > > >> >> > > V2 - updated the commit message based on Peter's comments >> >> > > >> >> > > V3 - removed u8 casting based on Peter's comments, cleaned up= and >> >> > > simplified the change by using raw I/O functions rather than >> >> > > using in_be32 & out_be32 functions. >> >> > >> >> > The __raw_{read,write}l() functions aren't the best choice here= =2E >> >> > =A0User >> >> > ioread32be(), iowrite32be() instead if you want them to work >> >> > cross-architecture (see include/asm-generic/iomap.h). >> >> >> >> Maybe the ioread functions will work better than the in/out_be32 = as >> >> they >> >> were not working like I wanted. >> >> >> >> I'm still trying to get my head wrapped around the right I/O func= tions >> >> to use since there are so many >> >> options. >> >> >> >> I'll look at your suggestions. >> > >> > That works ok on Powerpc, but not microblaze yet as there are stil= l >> > patches in the process of going into the kernel for that. >> > >> > Do we need to wait til those patches are in? >> >> I'd make it broken in Kconfig on microblaze until those patches get >> merged. =A0To the best of my knowledge, the ioread/write routines ar= e >> the best functions to use for cross-architecture MMIO code. > > The MMIO patchset for MicroBlaze is in linux-next and Michal sent an = -rc2 > pull request to Linus on 11th March. > > Maybe I misunderstood Grant's meaning, but I think this uartlite > ioread/iowrite change must be conditional on the MicroBlaze MMIO patc= hset > being merged.=A0 uartlite is a core driver for MicroBlaze and it's no= t OK to > break it just for an MMIO purity tweak! Of course you're right. I was getting confused with the ll_temac driver change. Sorry. > Hopefully Linus will pull Michal's changes soon and this wil just res= olve > itself. Yeah, just wait for Michal's pull req to get processed before respinning the patch. g. -- To unsubscribe from this list: send the line "unsubscribe linux-serial"= in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html