From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mailrelay005.isp.belgacom.be (mailrelay005.isp.belgacom.be [195.238.6.171]) by ozlabs.org (Postfix) with ESMTP id E780ADE0DC for ; Wed, 26 Mar 2008 03:20:27 +1100 (EST) From: Laurent Pinchart To: Scott Wood Subject: Re: [PATCH] cpm_uart: Allocate DPRAM memory for SMC ports on CPM2-based platforms. Date: Tue, 25 Mar 2008 17:20:21 +0100 References: <20080325160331.GB15093@ld0162-tx32.am.freescale.net> In-Reply-To: <20080325160331.GB15093@ld0162-tx32.am.freescale.net> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart5977279.5zazmx9Ss5"; protocol="application/pgp-signature"; micalg=pgp-sha1 Message-Id: <200803251720.24667.laurentp@cse-semaphore.com> Cc: linuxppc-dev@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , --nextPart5977279.5zazmx9Ss5 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline On Tuesday 25 March 2008 17:03, Scott Wood wrote: > On Tue, Mar 25, 2008 at 04:34:46PM +0100, Laurent Pinchart wrote: > > On Tuesday 25 March 2008 15:58, Scott Wood wrote: > > > Please maintain backward compatibility with older device trees (by > > > checking the length of the second reg resource). At the very least, > > > update the device trees that are affected. > >=20 > > I haven't seen any CPM2-based board using SMC ports in the device trees= =20 > > available in arch/powerpc/boot/dts. >=20 > ep8248e I should have checked git head. My bad. I'll include the ep8248e device tre= e=20 in the next patch. > > Should I still maintain compatibility with older device trees ? Is ther= e=20 any=20 > > out-of-tree PQ2 boards using udbg and SMC ? >=20 > Yes, I've answered questions on the lists from at least one person using > a custom board with cpm2 smc. Are you sure it wasn't me ? ;-) > > What about printing a warning if the second reg resource has the wrong > > size ? >=20 > The only way you'll see the warning is if udbg is enabled. :-P >=20 > Will a CPM reset blow away the portion of muram that holds the SMC pram > pointer? If not (and I don't think it will), just return the device tree > reg resource as is currently done if the resource is the wrong size. Ok I'll do that. Should I add a warning message to tell people to update th= e=20 device tree ? > > > After this point, even if you don't reset the CPM, udbg printk is bro= ken > > > because you moved pram. The udbg disabling will have to be moved bef= ore > > > this. > >=20 > > Moving the SMC pram doesn't break udbg printk in itself. What will brea= k=20 it is=20 > > moving the TX BDs, but the end result is the same, moving pram will res= ult=20 in=20 > > udbg being broken. > >=20 > > The cpm_uart driver disable udbg before allocating the new BDs. What ab= out=20 > > moving that right before moving the parameter RAM ?=20 cpm_uart_request_port(),=20 > > which is called in between, already disables RX and TX on the port, so = we=20 > > won't loose any debug message. >=20 > cpm_uart_request_port() returns without doing that if it's a console > port. I think the current placement of the udbg disable will be fine. Ok. I'll prepare a new patch that maintains compatibility with old device=20 trees. Best regards, =2D-=20 Laurent Pinchart CSE Semaphore Belgium Chauss=E9e de Bruxelles, 732A B-1410 Waterloo Belgium T +32 (2) 387 42 59 =46 +32 (2) 387 42 75 --nextPart5977279.5zazmx9Ss5 Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.5 (GNU/Linux) iD8DBQBH6SZI8y9gWxC9vpcRAsRkAKCdb3vKJlIJhRSyuNwHwurk3ccy6wCg0pNV DpmDrLznaCwnz7k6B+7JCAA= =1Lz2 -----END PGP SIGNATURE----- --nextPart5977279.5zazmx9Ss5--