From mboxrd@z Thu Jan 1 00:00:00 1970 From: thierry.reding@gmail.com (Thierry Reding) Date: Tue, 26 Aug 2014 09:50:25 +0200 Subject: [PATCH v2 2/9] mailbox: Add NVIDIA Tegra XUSB mailbox driver In-Reply-To: <3804028.YQzQ4uAVsf@wuerfel> References: <1408381705-3623-1-git-send-email-abrestic@chromium.org> <53FB8820.4010202@wwwdotorg.org> <20140826065729.GC15573@ulmo> <3804028.YQzQ4uAVsf@wuerfel> Message-ID: <20140826075023.GB17263@ulmo> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Aug 26, 2014 at 09:43:50AM +0200, Arnd Bergmann wrote: > On Tuesday 26 August 2014 08:57:31 Thierry Reding wrote: > > On Mon, Aug 25, 2014 at 01:01:52PM -0600, Stephen Warren wrote: > > > On 08/18/2014 11:08 AM, Andrew Bresticker wrote: > > [...] > > > >+static int tegra_xusb_mbox_probe(struct platform_device *pdev) > > > > > > >+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > > > >+ if (!res) > > > >+ return -ENODEV; > > > > > > Should devm_request_mem_region() be called here to claim the region? > > > > > > >+ mbox->regs = devm_ioremap_nocache(&pdev->dev, res->start, > > > >+ resource_size(res)); > > > >+ if (!mbox->regs) > > > >+ return -ENOMEM; > > > > > > Is _nocache required? I don't see other drivers using it. I assume there's > > > nothing special about the mbox registers. > > > > Most drivers should be using devm_ioremap_resource() which will use the > > _nocache variant of devm_ioremap() when appropriate. Usually the region > > will not be marked cacheable (IORESOURCE_CACHEABLE) and therefore be > > remapped uncached. > > > > Note that ioremap() and ioremap_nocache() are the same. We really shouldn't > ever call ioremap_nocache(). Perhaps we should remove ioremap_nocache() in that case. Or ioremap(), really, and keep only those variants that do what they claim to do. > devm_ioremap_resource() and pci_iomap() checking for IORESOURCE_CACHEABLE is > rather silly, since it doesn't call ioremap_cache() in that case. Then that should be fixed. Thierry -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 819 bytes Desc: not available URL: