From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B3C05C433DB for ; Mon, 25 Jan 2021 16:25:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 64E82221E3 for ; Mon, 25 Jan 2021 16:25:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730656AbhAYQZt (ORCPT ); Mon, 25 Jan 2021 11:25:49 -0500 Received: from netrider.rowland.org ([192.131.102.5]:56689 "HELO netrider.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1730702AbhAYQXM (ORCPT ); Mon, 25 Jan 2021 11:23:12 -0500 Received: (qmail 147065 invoked by uid 1000); 25 Jan 2021 11:22:30 -0500 Date: Mon, 25 Jan 2021 11:22:30 -0500 From: Alan Stern To: Arnd Bergmann Cc: Greg Kroah-Hartman , Peter Chen , Dmitry Osipenko , Thierry Reding , Arnd Bergmann , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] usb: host: ehci-tegra: fix Kconfig depencies Message-ID: <20210125162230.GA145777@rowland.harvard.edu> References: <20210125113248.2268952-1-arnd@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210125113248.2268952-1-arnd@kernel.org> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jan 25, 2021 at 12:32:30PM +0100, Arnd Bergmann wrote: > From: Arnd Bergmann > > Selecting the chipidea driver from the old Kconfig symbol > can lead to a missing dependency: Arnd: I found this whole patch a little confusing. For example, in the sentence above, what does "the old Kconfig symbol" refer to? Comparing the various Kconfig files, I see what the problem is. The commit which this one fixes made CONFIG_EHCI_TEGRA select CONFIG_USB_CHIPIDEA, but it didn't make EHCI_TEGRA depend on the things that USB_CHIPIDEA depends on. Can you please state this more explicitly in the patch description? > WARNING: unmet direct dependencies detected for USB_CHIPIDEA > Depends on [m]: USB_SUPPORT [=y] && (USB_EHCI_HCD [=y] && USB_GADGET [=m] || USB_EHCI_HCD [=y] && !USB_GADGET [=m] || !USB_EHCI_HCD [=y] && USB_GADGET [=m]) && HAS_DMA [=y] > Selected by [y]: > - USB_EHCI_TEGRA [=y] && USB_SUPPORT [=y] && USB [=y] && USB_EHCI_HCD [=y] && ARCH_TEGRA [=y] > aarch64-linux-ld: drivers/usb/chipidea/otg.o: in function `ci_handle_vbus_change': > otg.c:(.text+0x3c8): undefined reference to `usb_gadget_vbus_connect' > aarch64-linux-ld: otg.c:(.text+0x42c): undefined reference to `usb_gadget_vbus_disconnect' > aarch64-linux-ld: drivers/usb/chipidea/otg.o: in function `ci_otg_work': > otg.c:(.text+0x5d4): undefined reference to `usb_gadget_vbus_disconnect' > ... > > Duplicate the dependency to ensure that this driver can > only be a loadable module if one of its dependencies is. > > Fixes: c3590c7656fb ("usb: host: ehci-tegra: Remove the driver") > Signed-off-by: Arnd Bergmann > --- > drivers/usb/host/Kconfig | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig > index 160e5d3927e2..66b01b619ecd 100644 > --- a/drivers/usb/host/Kconfig > +++ b/drivers/usb/host/Kconfig > @@ -269,6 +269,7 @@ config USB_EHCI_HCD_AT91 > config USB_EHCI_TEGRA > tristate "NVIDIA Tegra HCD support" > depends on ARCH_TEGRA > + depends on ((USB_EHCI_HCD && USB_GADGET) || (USB_EHCI_HCD && !USB_GADGET) || (!USB_EHCI_HCD && USB_GADGET)) && HAS_DMA > select USB_CHIPIDEA > select USB_CHIPIDEA_HOST > select USB_CHIPIDEA_TEGRA Isn't there at least one other missing dependency? This entry selects USB_CHIPIDEA_TEGRA, which depends on OF. So shouldn't this entry also depend on OF? Or does the Kconfig system detect that for us? Also, while I'm no expert on the Kconfig language, it seems that the new "depends" line could be a lot easier to understand if it was refactored with some comments added. Yes, I realize you just copied the existing dependency from the USB_CHIPIDEA entry -- that one could stand to be cleaned up as well. For instance, how about putting the HAS_DMA part into a separate line, since it's unrelated to the other stuff? And the rest looks like it could be changed to: depends on USB_EHCI_HCD || USB_GADGET although that probably isn't quite valid. Still, can't it be changed to something simpler than (USB_EHCI_HCD && USB_GADGET) || (USB_EHCI_HCD && !USB_GADGET) || (!USB_EHCI_HCD && USB_GADGET) ? Alan Stern