From: Ben Hutchings Date: Fri, 5 Oct 2012 22:35:41 +0000 (+0100) Subject: sfc: Rework IRQ enable/disable X-Git-Tag: v3.12-rc1~132^2~185^2~10 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d829118705f8213ffeffa4fefa8931dea6b7f016;p=pandora-kernel.git sfc: Rework IRQ enable/disable There are many problems with the current efx_stop_interrupts() and efx_start_interrupts(): 1. On Siena, it is unsafe to disable the master IRQ enable bit (DRV_INT_EN_KER) while any IRQ sources are enabled. 2. On EF10 there is no master IRQ enable bit, so we cannot expect to defer IRQs without tearing down event queues. (Though I don't think we will need to keep any event queues around while the device is down, as we do for VFDI on Siena.) 3. synchronize_irq() only waits for a running IRQ handler to finish, not for any propagation through IRQ controllers. Therefore an IRQ may still be received and handled after efx_stop_interrupts() returns. IRQ handlers can then race with channel reallocation. To fix this: a. Introduce a software IRQ enable flag. So long as this is clear, IRQ handlers will only acknowledge IRQs and not touch the channel structures. b. Define a new struct efx_msi_context as the context for MSIs. This is never reallocated and is sufficient to find the software enable flag and the channel structure. It also includes the channel/IRQ name, which was previously separated out as it must also not be reallocated. c. Split efx_{start,stop}_interrupts() into efx_{,soft_}_{enable,disable}_interrupts(). The 'soft' functions don't touch the hardware master enable flag (if it exists) and don't reinitialise or tear down channels with the keep_eventq flag set. Signed-off-by: Ben Hutchings --- Reading git-diff-tree failed