From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [PATCH v3 0/9] Tegra xHCI support Date: Tue, 16 Sep 2014 17:03:35 -0600 Message-ID: <5418C1C7.90404@wwwdotorg.org> References: <1409693701-16520-1-git-send-email-abrestic@chromium.org> <54172B3F.9030901@wwwdotorg.org> <54185698.7020600@wwwdotorg.org> <5418BC5C.5020108@wwwdotorg.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Andrew Bresticker Cc: Tomeu Vizoso , Thierry Reding , "linux-tegra@vger.kernel.org" , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Russell King , Jassi Brar , Linus Walleij , Greg Kroah-Hartman , Mathias Nyman , Grant Likely , Alan Stern , Arnd Bergmann , Kishon Vijay Abraham I , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" List-Id: linux-tegra@vger.kernel.org On 09/16/2014 04:51 PM, Andrew Bresticker wrote: > On Tue, Sep 16, 2014 at 3:40 PM, Stephen Warren wrote: >> On 09/16/2014 10:57 AM, Andrew Bresticker wrote: >>> On Tue, Sep 16, 2014 at 8:26 AM, Stephen Warren wrote: >>>> The XHCI driver can't load its firmware unless it's a module; if I make it >>>> built-in, it fails immediately with error -2 during "Direct firmware >>>> loading". The driver needs to work with either immediate or deferred >>>> firmware loading. >>> >>> >>> If you want the driver to be built-in, you'll either need to build the >>> firmware in as well (i.e. EXTRA_FIRMWARE) or enable >>> FW_LOADER_USER_HELPER_FALLBACK to load with userspace/uevent (though >>> apparently this is deprecated). >> >> >> Hmm. I didn't have to do that for the Atmel touchpad driver to work, but >> perhaps it's just ignoring a firmware loading error, and continuing with >> whatever is in the device's flash already. >> >> It seems odd that such a fundamental feature would require a deprecated >> Kconfig option. Is there some replacement that does the same thing that >> isn't deprecated? The Kconfig help for the option doesn't say anything >> useful... >> >> Oh, this option doesn't actually seem to work. I see the following in dmesg: >> >>> [root@swarren-dt ~]# dmesg|grep -i -e xhci -e firmware >>> [ 1.461773] xhci-tegra 70090000.usb: Failed to get supply 'avddio-pex': >>> -517 >>> [ 1.468930] platform 70090000.usb: Driver xhci-tegra requests probe >>> deferral >>> [ 2.567966] xhci-tegra 70090000.usb: Direct firmware load for >>> nvidia/tegra124/xusb.bin failed with error -2 >>> [ 2.577786] xhci-tegra 70090000.usb: Falling back to user helper >> >> >> ... but: >> >> [root@swarren-dt ~]# lsusb >> unable to initialize libusb: -99 >> >> Perhaps systemd-udevd doesn't implement firmware loading; is it user-space >> udev that's deprecated implementing user-space firmware loading, rather than >> the kernel deprecating support for calling out to user space? > > I believe it is userspace udev that has deprecated user firmware > loading. The kernel still does call out to userspace. Alternatively, > you could use the firmware_class loading interface described in > Documentation/firmware_class/README, but that kind of sucks too. > >> This sucks, because now I can't just TFTP boot kernels but somehow have to >> get updated kernel modules onto my device every time before testing a new >> kernel build. > > Yeah... it does. I get around this by building the firmware into the > kernel image (i.e. CONFIG_EXTRA_FIRMWARE), which is also your only > option if the root device happens to be on USB. Unfortunately, I'm > not aware of any other alternatives. Ah right, CONFIG_EXTRA_FIRMWARE does work, although it's not something I can put into tegra_defconfig for people. I suppose we'll have to make it =m in tegra_defconfig, and anyone who wants to build it in will have to carry a local patch to add the firmware to their kernel source tree. At least with "git add" of the firmware, it won't disappear from disk upon "git clean ...".