From 86b5e86e5bb0192114f32a6e3fd6046d0db2c6e4 Mon Sep 17 00:00:00 2001 From: Yo-Jung Lin <0xff07@gmail.com> Date: Sat, 20 Apr 2024 12:32:36 +0800 Subject: [PATCH] Refine description in request_threaded_irq usage --- lkmpg.tex | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/lkmpg.tex b/lkmpg.tex index 1348da4..bc0b78d 100644 --- a/lkmpg.tex +++ b/lkmpg.tex @@ -1957,7 +1957,8 @@ Usage of other parameters are the same as \cpp|request_irq()|. Presence of both handlers is not mandatory. If either of them is not needed, pass the \cpp|NULL| instead. -A \cpp|NULL| top-half handler implicitly means doing nothing but waking up the bottom-half serving thread (for running the bottom-half handler); A \cpp|NULL| bottom-half handler would have the same effect as if \cpp|request_irq()| were used. +A \cpp|NULL| top-half handler implies that no action is taken except to wake up the bottom-half serving thread, which runs the bottom-half handler. +Similarly, a \cpp|NULL| bottom-half handler effectively acts as if \cpp|request_irq()| were used. In fact, this is how \cpp|request_irq()| is implemented. Note that passing \cpp|NULL| to both handlers is considered an error and will make registration fail.