| Message ID | 1306235508-3843-1-git-send-email-dave.martin@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
diff --git a/arch/arm/include/asm/fiq.h b/arch/arm/include/asm/fiq.h index 2242ce2..d6e4b99 100644 --- a/arch/arm/include/asm/fiq.h +++ b/arch/arm/include/asm/fiq.h @@ -4,6 +4,13 @@ * Support for FIQ on ARM architectures. * Written by Philip Blundell <philb@gnu.org>, 1998 * Re-written by Russell King + * + * NOTE: The FIQ mode registers are not magically preserved across + * suspend/resume. + * + * Drivers which require these registers to be preserved across power + * management operations must implement appropriate suspend/resume handlers to + * save and restore them. */ #ifndef __ASM_FIQ_H
Drivers which make use of the FIQ interrupt may require the state of the FIQ mode registers to be preserved across suspend/resume. Because the FIQ mode registers are not saved and restored automatically by the kernel, driver authors will need to do the appropriate save/restore in their own driver suspend/resume handlers. Implementing global automatic save/restore of the FIQ state does not appear appropriate, since this by itself is not sufficient for FIQ-based drivers to function correctly across suspend/resume in any case. This patch adds a brief explanatory note to fiq.h documenting the requirement placed on driver authors. Signed-off-by: Dave Martin <dave.martin@linaro.org> --- KernelVersion: v2.6.39