Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Tue, 10 May 2022 14:58:48 +0200
From:   Thomas Pfaff <tpfaff@pcs.com>
To:     Thomas Gleixner <tglx@linutronix.de>
CC:     <linux-kernel@vger.kernel.org>, <linux-rt-users@vger.kernel.org>
Subject: Re: [PATCH v3] irq/core: synchronize irq_thread startup
In-Reply-To: <87mtfppqi8.ffs@tglx>
Message-ID: <b8e4951a-212a-ea30-662-b13a65cad3b7@pcs.com>
References: <552fe7b4-9224-b183-bb87-a8f36d335690@pcs.com> <87mtg0m2jb.ffs@tglx> <e64aa9cb-a1ae-7534-8bf1-446d9d8c512@pcs.com> <87pmklpqod.ffs@tglx> <87mtfppqi8.ffs@tglx>
MIME-Version: 1.0
Content-Type: text/plain; charset="US-ASCII"
X-KSE-AttachmentFiltering-Interceptor-Info: protection disabled
X-KSE-Antivirus-Interceptor-Info: scan successful
X-KSE-Antivirus-Info: Clean, bases: 10.05.2022 10:11:00
X-KSE-BulkMessagesFiltering-Scan-Result: protection disabled
X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,SPF_HELO_NONE,
        SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no
        version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org


On Tue, 10 May 2022, Thomas Gleixner wrote:

> It does matter whether the synchronization is done via
> __synchronize_hardirq() or via synchronize_irq(). The latter ensured
> that the thread reached the thread function and handled the pending
> wakeup _before_ kthread_stop() become true.
> 
> So the fix is required to undo the damage created by 519cc8652b3a.
> 
> The synchronize_irq() after free_irq() is a completely different
> problem.

Thank you for the clarification.
I was unsure if I missed something.

    Thomas