From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754111Ab2KQKPw (ORCPT ); Sat, 17 Nov 2012 05:15:52 -0500 Received: from mga11.intel.com ([192.55.52.93]:38719 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753200Ab2KQKPt (ORCPT ); Sat, 17 Nov 2012 05:15:49 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.83,270,1352102400"; d="scan'208";a="250629949" Date: Sat, 17 Nov 2012 12:18:59 +0200 From: Mika Westerberg To: "Rafael J. Wysocki" Cc: linux-kernel@vger.kernel.org, lenb@kernel.org, rafael.j.wysocki@intel.com, broonie@opensource.wolfsonmicro.com, grant.likely@secretlab.ca, linus.walleij@linaro.org, khali@linux-fr.org, ben-linux@fluff.org, w.sang@pengutronix.de, bhelgaas@google.com, mathias.nyman@linux.intel.com, linux-acpi@vger.kernel.org Subject: Re: [PATCH v2 2/3] spi / ACPI: add ACPI enumeration support Message-ID: <20121117101859.GD17774@intel.com> References: <1352977397-2280-1-git-send-email-mika.westerberg@linux.intel.com> <1352977397-2280-3-git-send-email-mika.westerberg@linux.intel.com> <2716271.5hiFYsNu5c@vostro.rjw.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2716271.5hiFYsNu5c@vostro.rjw.lan> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Nov 17, 2012 at 11:11:59AM +0100, Rafael J. Wysocki wrote: > > +static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level, > > + void *data, void **return_value) > > +{ > > + struct spi_master *master = data; > > + struct resource_list_entry *rentry; > > + struct list_head resource_list; > > + struct acpi_device *adev; > > + struct spi_device *spi; > > + int ret; > > + > > + if (acpi_bus_get_device(handle, &adev)) > > + return AE_OK; > > + if (acpi_bus_get_status(adev) || !adev->status.present) > > + return AE_OK; > > + > > + spi = spi_alloc_device(master); > > + if (!spi) { > > + dev_err(&master->dev, "failed to allocate SPI device for %s\n", > > + dev_name(&adev->dev)); > > + return AE_NO_MEMORY; > > + } > > + > > + INIT_LIST_HEAD(&resource_list); > > + ret = acpi_dev_get_resources(adev, &resource_list, > > + acpi_spi_add_resource, spi); > > + if (ret < 0) > > + goto fail_put_dev; > > + > > + list_for_each_entry(rentry, &resource_list, node) { > > + struct resource *r = &rentry->res; > > + > > + if (resource_type(r) == IORESOURCE_IRQ) { > > + spi->irq = r->start; > > + break; > > + } > > + } > > + > > + acpi_dev_free_resource_list(&resource_list); > > A potential problem is lurking here, or rather two of them. > > Suppose there are multiple IRQ resources for this device. The code > above will cause GSIs to be registered for all of them, but we'll > use only one eventually. Moreover, we'll use the last one, but > perhaps we should use the first one instead? Indeed we should use the first one. > Maybe a better approach would be to make acpi_spi_add_resource() > call acpi_dev_resource_interrupt(ares, 0, &r) directly and then skip all of > the remaining IRQ resources if it finds one? > > For example set spi->irq to -1 initially, assign it if an IRQ > resource is found and skip all of the remaining IRQ resources if > it is non-negative? OK, will do. Thanks.