Re: [PATCHv4 02/11] pci: use weak functions for MSI arch-specific functions
From: Thomas Petazzoni <hidden>
Date: 2013-07-02 05:30:37
Also in:
linux-arm-kernel, linux-mips
Dear Michael Ellerman, On Tue, 02 Jul 2013 10:53:16 +1000, Michael Ellerman wrote:
On Mon, 2013-07-01 at 15:42 +0200, Thomas Petazzoni wrote:quoted
Until now, the MSI architecture-specific functions could be overloaded using a fairly complex set of #define and compile-time conditionals. In order to prepare for the introduction of the msi_chip infrastructure, it is desirable to switch all those functions to use the 'weak' mechanism. This commit converts all the architectures that were overidding those MSI functions to use the new strategy.The MSI code used to use weak functions, until we discovered they were being miscompiled on some toolchains (11df1f0). I assume these days we're confident they work correctly.
Hum, interesting. I see from your commit that gcc 4.3.2 was apparently affected, and gcc 4.3.x is not /that/ old. Bjorn, what's your point of view on this? Another option would be to have architecture register some msi_arch_ops structure, with a set of operations, which I believe is a pattern that is more widespread in the kernel than weak functions. Thoughts? Thomas -- Thomas Petazzoni, Free Electrons Kernel, drivers, real-time and embedded Linux development, consulting, training and support. http://free-electrons.com