From patchwork Wed Dec 6 10:12:31 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tomi Valkeinen X-Patchwork-Id: 13481409 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="mlZdKuCI" Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 80E91D64; Wed, 6 Dec 2023 02:13:00 -0800 (PST) Received: from [127.0.1.1] (91-158-149-209.elisa-laajakaista.fi [91.158.149.209]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 8EA622B09; Wed, 6 Dec 2023 11:12:13 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1701857534; bh=PKUcBdc8Qj6XeTMDCk4F0nRr2AQygA1lnSwR9BIZ64A=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=mlZdKuCICZ5xqmYpghtsHBC1xpLI76Ws+DZsoYvWi8URIodqTSDt9hGX+aot1nvHW C9gdyHqwHmp09usqo56v9453JXWr3org8nQ9xwPX54CN1RXnilaS1EasyJKBLFCxSe /KhuS6lrDaxHWLYIpJpq4Jg4LfbyItKa0/eQnoBk= From: Tomi Valkeinen Date: Wed, 06 Dec 2023 12:12:31 +0200 Subject: [PATCH v2 4/4] media: rkisp1: Fix IRQ disable race issue Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20231206-rkisp-irq-fix-v2-4-6ba4185eeb1f@ideasonboard.com> References: <20231206-rkisp-irq-fix-v2-0-6ba4185eeb1f@ideasonboard.com> In-Reply-To: <20231206-rkisp-irq-fix-v2-0-6ba4185eeb1f@ideasonboard.com> To: Dafna Hirschfeld , Laurent Pinchart , Mauro Carvalho Chehab , Heiko Stuebner , Paul Elder Cc: Alexander Stein , kieran.bingham@ideasonboard.com, umang.jain@ideasonboard.com, aford173@gmail.com, linux-media@vger.kernel.org, linux-rockchip@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Tomi Valkeinen X-Mailer: b4 0.12.4 X-Developer-Signature: v=1; a=openpgp-sha256; l=3439; i=tomi.valkeinen@ideasonboard.com; h=from:subject:message-id; bh=PKUcBdc8Qj6XeTMDCk4F0nRr2AQygA1lnSwR9BIZ64A=; b=owEBbQKS/ZANAwAIAfo9qoy8lh71AcsmYgBlcEkhuPu8R/u0zTPQ1W//B0yzANJaz5h46O91S MX9rZ0rGhKJAjMEAAEIAB0WIQTEOAw+ll79gQef86f6PaqMvJYe9QUCZXBJIQAKCRD6PaqMvJYe 9SQ1D/0WNlBX1kQYLY1htxMCKTBE6WutW9vj9EDMkljHP4bFOTt76UdikAxDBt1ozRlskCeF6cE PNe0r5Ck2WlI7E+Ucfu1SmRgsqZf80Or7Lz3sqGYscuwl5RF1QUYnzmULiaNOSmkkJHc/ZIIemb p+G7vvjytJrpg1MGF/qJmhVlGCVZJhLn+r8oAHx80cCgzvnf9apfFuz0soMDZLzC60zk1TK9+/F mjhOSBnU8njOvS7TdFQJsxhr5fCWsZYXahNF41pY+luL+ZgS7KNpbkqprCw1k63yeO6XABJ9pAh Cyx7CtSaKsrLGO7GhnKZpcrO7cdQROBDpG4ymbwxFVMKnED45uChqhg9y663qTHBahXIVUhuyBX QwKPpwY7wFCORjm0WtGPW7dfE8Mgam1vqPHnzfi7s/JDZQMKNZvr1jlG3wgbHgF6/U7ngoDiR4E 2U1qi4jqTB/V2vAKvSfqkJ1Zc4DcssxYYOcmO3iQVPkNCiBHwdXzttxza0KTWktARVZ5lyIaEXE hxTlkWxglasejh0NocZF5jfIeOPfHV5JhHFOmJ/6iaLAo1IEgFRRe5QGsm267E6IW3Obuk9+DZ1 4rNodgTAdPKsYrQNbUDie5BXKjTjOwZUJ/uvb0/aKOm0G/15ajtHheOslDXihbxjSBiiX1RlVSW Ckl3LxDwT6v/JPA== X-Developer-Key: i=tomi.valkeinen@ideasonboard.com; a=openpgp; fpr=C4380C3E965EFD81079FF3A7FA3DAA8CBC961EF5 In rkisp1_isp_stop() and rkisp1_csi_disable() the driver masks the interrupts and then apparently assumes that the interrupt handler won't be running, and proceeds in the stop procedure. This is not the case, as the interrupt handler can already be running, which would lead to the ISP being disabled while the interrupt handler handling a captured frame. This brings up two issues: 1) the ISP could be powered off while the interrupt handler is still running and accessing registers, leading to board lockup, and 2) the interrupt handler code and the code that disables the streaming might do things that conflict. It is not clear to me if 2) causes a real issue, but 1) can be seen with a suitable delay (or printk in my case) in the interrupt handler, leading to board lockup. Signed-off-by: Tomi Valkeinen Reviewed-by: Laurent Pinchart --- drivers/media/platform/rockchip/rkisp1/rkisp1-csi.c | 14 +++++++++++++- drivers/media/platform/rockchip/rkisp1/rkisp1-isp.c | 20 +++++++++++++++++--- 2 files changed, 30 insertions(+), 4 deletions(-) diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-csi.c b/drivers/media/platform/rockchip/rkisp1/rkisp1-csi.c index 47f4353a1784..0bab3303f2e4 100644 --- a/drivers/media/platform/rockchip/rkisp1/rkisp1-csi.c +++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-csi.c @@ -125,8 +125,20 @@ static void rkisp1_csi_disable(struct rkisp1_csi *csi) struct rkisp1_device *rkisp1 = csi->rkisp1; u32 val; - /* Mask and clear interrupts. */ + /* Mask MIPI interrupts. */ rkisp1_write(rkisp1, RKISP1_CIF_MIPI_IMSC, 0); + + /* Flush posted writes */ + rkisp1_read(rkisp1, RKISP1_CIF_MIPI_IMSC); + + /* + * Wait until the IRQ handler has ended. The IRQ handler may get called + * even after this, but it will return immediately as the MIPI + * interrupts have been masked. + */ + synchronize_irq(rkisp1->irqs[RKISP1_IRQ_MIPI]); + + /* Clear MIPI interrupt status */ rkisp1_write(rkisp1, RKISP1_CIF_MIPI_ICR, ~0); val = rkisp1_read(rkisp1, RKISP1_CIF_MIPI_CTRL); diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-isp.c b/drivers/media/platform/rockchip/rkisp1/rkisp1-isp.c index dafbfd230542..33b5a714d117 100644 --- a/drivers/media/platform/rockchip/rkisp1/rkisp1-isp.c +++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-isp.c @@ -364,11 +364,25 @@ static void rkisp1_isp_stop(struct rkisp1_isp *isp) * ISP(mi) stop in mi frame end -> Stop ISP(mipi) -> * Stop ISP(isp) ->wait for ISP isp off */ - /* stop and clear MI and ISP interrupts */ - rkisp1_write(rkisp1, RKISP1_CIF_ISP_IMSC, 0); - rkisp1_write(rkisp1, RKISP1_CIF_ISP_ICR, ~0); + /* Mask MI and ISP interrupts */ + rkisp1_write(rkisp1, RKISP1_CIF_ISP_IMSC, 0); rkisp1_write(rkisp1, RKISP1_CIF_MI_IMSC, 0); + + /* Flush posted writes */ + rkisp1_read(rkisp1, RKISP1_CIF_MI_IMSC); + + /* + * Wait until the IRQ handler has ended. The IRQ handler may get called + * even after this, but it will return immediately as the MI and ISP + * interrupts have been masked. + */ + synchronize_irq(rkisp1->irqs[RKISP1_IRQ_ISP]); + if (rkisp1->irqs[RKISP1_IRQ_ISP] != rkisp1->irqs[RKISP1_IRQ_MI]) + synchronize_irq(rkisp1->irqs[RKISP1_IRQ_MI]); + + /* Clear MI and ISP interrupt status */ + rkisp1_write(rkisp1, RKISP1_CIF_ISP_ICR, ~0); rkisp1_write(rkisp1, RKISP1_CIF_MI_ICR, ~0); /* stop ISP */