From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753595AbaKLXID (ORCPT ); Wed, 12 Nov 2014 18:08:03 -0500 Received: from mezzanine.sirena.org.uk ([106.187.55.193]:35641 "EHLO mezzanine.sirena.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752545AbaKLXIA (ORCPT ); Wed, 12 Nov 2014 18:08:00 -0500 Date: Wed, 12 Nov 2014 23:06:24 +0000 From: Mark Brown To: Andrew Bresticker Cc: James Hartley , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Grant Likely , Ezequiel Garcia , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , linux-spi@vger.kernel.org Message-ID: <20141112230624.GA3815@sirena.org.uk> References: <1415828274-24727-1-git-send-email-abrestic@chromium.org> <1415828274-24727-3-git-send-email-abrestic@chromium.org> <20141112220740.GR3815@sirena.org.uk> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="HmqCnFV+ySQ80OU5" Content-Disposition: inline In-Reply-To: X-Cookie: Some optional equipment shown. User-Agent: Mutt/1.5.23 (2014-03-12) X-SA-Exim-Connect-IP: 94.175.94.161 X-SA-Exim-Mail-From: broonie@sirena.org.uk Subject: Re: [PATCH 2/2] spi: Add driver for IMG SPFI controller X-SA-Exim-Version: 4.2.1 (built Mon, 26 Dec 2011 16:24:06 +0000) X-SA-Exim-Scanned: Yes (on mezzanine.sirena.org.uk) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --HmqCnFV+ySQ80OU5 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Wed, Nov 12, 2014 at 02:54:57PM -0800, Andrew Bresticker wrote: > On Wed, Nov 12, 2014 at 2:07 PM, Mark Brown wrote: > >> drivers/spi/spi-img.c | 703 ++++++++++++++++++++++++++++++++++++++++++++++++++ > > How about spi-img-spfi? That way if someone makes another SPI > > controller (say a more generic one, this one seems flash specialized) > > there won't be a collision. > Despite the name, I believe this controller is used for generic SPI > stuff as well. I'm not sure if there is a separate one which is more > generic (James?). It would still be better to use a name less impressively generic - this is an entire company, not even a product line. > >> + cpu_relax(); > > Seems random - we already relax in the data transfer? > We don't relax in the transfers - would that be a better place to put > it? I thought it was better here since we reach this point once the > TX FIFO has filled or RX FIFO has emptied. Oh, that was the FIFO drain I was thinking of. I guess here is fine. > >> + if (tx_buf) > >> + spfi_flush_tx_fifo(spfi); > >> + spfi_disable(spfi); > > What does the enable and disable actually do? Should this be runtime > > PM? > It starts/stops the transfer. The control registers (bit clock, > transfer mode, etc.) must be programmed before the enable bit is set > and the bit does not clear itself upon completion of the transfer. I > don't think it makes sense to have this be part of runtime PM. Perhaps these functions need to be called start() and stop() then - the names sound like they gate the IP? > > This will unconditionally claim to have handled an interrupt even if it > > didn't get any interrupt status it has ever heard of. At the very least > > it should log unknown interrupts, ideally return IRQ_NONE though since > > it seems to be a clear on read interrupt that's a bit misleading. > There's a clear register actually (see the writel() above), but yes, > an error and returning IRQ_NONE sound appropriate in the event of an > unexpected interrupt. Don't add the error print - the interrupt core has diagnostics already and it won't be nice if the interrupt ends up shared. My recommendation was intended as an either/or. --HmqCnFV+ySQ80OU5 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQEcBAEBAgAGBQJUY+fwAAoJECTWi3JdVIfQ8+AH/iKP7McJD0aZPpdX46LKx+HX KqmdqIQAipOA5CKYEXcSNnX0RbzJ1+odvGgxjnOET0KddT85SWAXqjI9ZAq5gQQQ Kqj1SdOJ1t6lMXEmePAYlGHiWqSwrGXf+XGemwEfj20UBPmBA0u9VUvTxDYBvXeA m44PvzhXER2yvhIJd2QOQ15DDU+6CqAMXvK4ESgrfJNWMB2tHNTNRhHsUYSsvuKj iQAt3X+IpXbzmAnSjW1wVjke5TU/ncowYz0V0pYMeJieB1xluEjMWQNoJCXq9KLl aG/E9Mk1saDw2Dnx/sf8zD/Oq+1OSgfU+X814KGyy5smROC2cA+6PDxW5yZFIU8= =tazb -----END PGP SIGNATURE----- --HmqCnFV+ySQ80OU5--