Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754627AbbEMRqr (ORCPT ); Wed, 13 May 2015 13:46:47 -0400 Received: from mail-qc0-f174.google.com ([209.85.216.174]:34241 "EHLO mail-qc0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754332AbbEMRqo (ORCPT ); Wed, 13 May 2015 13:46:44 -0400 Date: Wed, 13 May 2015 13:46:40 -0400 From: Tejun Heo To: Robert Richter Cc: Robert Richter , Catalin Marinas , Will Deacon , Sunil Goutham , Jiang Liu , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org, Alexander Gordeev Subject: Re: [PATCH v2] AHCI: Add generic MSI-X interrupt support to SATA PCI driver Message-ID: <20150513174640.GZ11388@htj.duckdns.org> References: <20150513143353.GU11388@htj.duckdns.org> <20150513143906.GV11388@htj.duckdns.org> <20150513172828.GA8449@rric.localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150513172828.GA8449@rric.localhost> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1390 Lines: 36 Hello, Robert. On Wed, May 13, 2015 at 07:28:28PM +0200, Robert Richter wrote: > > > This looks not very useful to do. Since irq is used only a single > > > time, there is no reason to store it in the host's data structure. It > > > > Doesn't really matter tho. > > Since ahci_host_activate() is EXPORT_SYMBOL_GPL I really have concerns > changing the i/f. But I will send you a patch for this. It doesn't matter. Please go ahead and change it. > > Let's start with why we're doing this in the first place. > > Right, the sata controller is connected to a pci ecam controller, both > are on an SoC together with the processor. There are no external pci > ports for the connection of external devices. Since all pci devices on > the chip support msi-x, the controller is only capable to handle this > and not INTx nor MSI. So for enabling of the sata hc we need msix > support. I see. If you can get hold of an ahci controller which actually can do multi-irq msix, it'd be the best. If not, let's make it super clear that this is a special case and use it as the last resort (which also clers up the warning issue). Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/