From mboxrd@z Thu Jan 1 00:00:00 1970 From: arnd@arndb.de (Arnd Bergmann) Date: Sun, 19 Sep 2010 19:09:46 +0200 Subject: [PATCH 0/3] [ARM] tegra: PCI Express support In-Reply-To: <20100919164040.GG9098@n2100.arm.linux.org.uk> References: <201009191834.44928.arnd@arndb.de> <20100919164040.GG9098@n2100.arm.linux.org.uk> Message-ID: <201009191909.46371.arnd@arndb.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Sunday 19 September 2010 18:40:40 Russell King - ARM Linux wrote: > which works fine - and yes, if you insert an ISA driver it probably will > crash. But then you can crash an x86 PC by using setserial to define > a serial port at a wrong address. Sure, if you build the kernel just for one machine, there is no reason to include code that tries to access fixed I/O ports. What I'm more worried about is that as we're moving to multi-platform kernels you want to build for other hardware, e.g. one that has a PC-style keyboard controller and one that has a funny mapping like that. Normally, the driver for the keyboard controller should just access the well-known port number and not find anything there, because PCI devices are mapped above port 0x1000. What you get instead is a kernel NULL pointer access. Arnd