From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH 8/8] ARM: tegra: HACK: remove set_irq_flags() from driver Date: Thu, 1 Mar 2012 20:38:27 +0000 Message-ID: <201203012038.28062.arnd@arndb.de> References: <1330630010-11241-1-git-send-email-alan@signal11.us> <1330630010-11241-9-git-send-email-alan@signal11.us> <74CDBE0F657A3D45AFBB94109FB122FF17BE86173C@HQMAIL01.nvidia.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <74CDBE0F657A3D45AFBB94109FB122FF17BE86173C@HQMAIL01.nvidia.com> Sender: linux-kernel-owner@vger.kernel.org To: Stephen Warren Cc: Alan Ott , Russell King , Colin Cross , Olof Johansson , Grant Likely , Linus Walleij , Alan Stern , Greg Kroah-Hartman , Lucas De Marchi , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "linux-tegra@vger.kernel.org" , "linux-usb@vger.kernel.org" List-Id: linux-tegra@vger.kernel.org On Thursday 01 March 2012, Stephen Warren wrote: > > Alan Ott wrote at Thursday, March 01, 2012 12:27 PM: > > From: Arnd Bergmann > > > > The driver should not call set_irq_flags itself, and > > Probably true in this case. > > > cannot do this from a loadable module. > > I hope that's not true; grep'ing the entire of drivers/ shows a bunch > of drivers calling this function, and many look like they'd be reasonable > as module. The drivers that I can see using it are for the most part implementing irq controllers by themselves, which is different from merely using an interrupt. There are three exceptions today: arnd@klappe2:~/linux-arm$ git grep -l set_irq_flags drivers/ | xargs grep -L irq_chip drivers/tty/serial/serial_ks8695.c drivers/tty/serial/sirfsoc_uart.c drivers/usb/host/ehci-tegra.c > From what little I understand of this, any irq_chip is going to call > that function after setting up any child/cascaded IRQs, and I assume > that irq_chips can be in modules. But the function is not exported. I guess if we want to allow irq_chips in loadable modules, we could export it, but I don't see how it could ever have worked so far. > > Remove the call for now, which might break the driver > > but at least lets the kernel link again. > > The driver appears to work fine with this removed. At least, on Tegra20 > Harmony, I was able to modprobe ehci-hcd and then use the USB Ethernet > controller for DHCP and SSH. Ok, maybe it was the right fix after all then and it just needs a proper change description ;-) Arnd