From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F2378149C69; Fri, 6 Dec 2024 14:56:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733496999; cv=none; b=I4QmmRI7OfBPk9lnmSxS0RvUSJcHMuK3kVHDS6Irk+09rVwuN+3FeIhI+v10LA7gYfHmVhHj6B5DIo04dmttmcHd4Oy/d5jI8PdC1AsUZj4b/ZwNsG+D/9iCgbVc2pvRUpbs3sPw/pOSIGqIkK6GSdruLJP+yLSwwwFsRJAQUYU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733496999; c=relaxed/simple; bh=Ulf8KwSRVGllHQsvxRCBG8FmMvB7NejFvQLp0jnVijI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=sJ/zOTRb/S5Il625AnOXE5j/AlG7+/Tuy6ojct1nSKk2DghgCJ6292NTuJV/TryP5w5pNJmBrE2oHpaRbzAdlz5nMnIshNZIxM/oDa1hD6Ph2M/Jxx8epIe/cDzq4esSthG4SXMKGtmOSDlpBpHEhnPH9aOYQMe0ArFo4p40hpE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=SPrslKII; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="SPrslKII" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 786A1C4CED1; Fri, 6 Dec 2024 14:56:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1733496998; bh=Ulf8KwSRVGllHQsvxRCBG8FmMvB7NejFvQLp0jnVijI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SPrslKIIOcE0u7KwQcKtxq182/DhtuPma/U618jbzHlTTJnlrYE2CVFRDLv0Ix18P Fw6Ko3BHFlCTSeoYQHaaoiGq7fFIigJNvb6WscZNOanKc8TFjM++oksHBqr03T7YlS aoNPwP3qUHOQKcgogfdweGYBQpv2t7X3PBFibX9Y= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Dom Cobley , Maxime Ripard , Dave Stevenson , Sasha Levin Subject: [PATCH 6.6 166/676] drm/vc4: hdmi: Avoid hang with debug registers when suspended Date: Fri, 6 Dec 2024 15:29:45 +0100 Message-ID: <20241206143659.835727307@linuxfoundation.org> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20241206143653.344873888@linuxfoundation.org> References: <20241206143653.344873888@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dom Cobley [ Upstream commit 223ee2567a55e4f80315c768d2969e6a3b9fb23d ] Trying to read /sys/kernel/debug/dri/1/hdmi1_regs when the hdmi is disconnected results in a fatal system hang. This is due to the pm suspend code disabling the dvp clock. That is just a gate of the 108MHz clock in DVP_HT_RPI_MISC_CONFIG, which results in accesses hanging AXI bus. Protect against this. Fixes: 25eb441d55d4 ("drm/vc4: hdmi: Add all the vc5 HDMI registers into the debugfs dumps") Signed-off-by: Dom Cobley Reviewed-by: Maxime Ripard Link: https://patchwork.freedesktop.org/patch/msgid/20240621152055.4180873-17-dave.stevenson@raspberrypi.com Signed-off-by: Dave Stevenson Signed-off-by: Sasha Levin --- drivers/gpu/drm/vc4/vc4_hdmi.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c index c6e986f71a26f..d4487f4cb3034 100644 --- a/drivers/gpu/drm/vc4/vc4_hdmi.c +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c @@ -179,6 +179,8 @@ static int vc4_hdmi_debugfs_regs(struct seq_file *m, void *unused) if (!drm_dev_enter(drm, &idx)) return -ENODEV; + WARN_ON(pm_runtime_resume_and_get(&vc4_hdmi->pdev->dev)); + drm_print_regset32(&p, &vc4_hdmi->hdmi_regset); drm_print_regset32(&p, &vc4_hdmi->hd_regset); drm_print_regset32(&p, &vc4_hdmi->cec_regset); @@ -188,6 +190,8 @@ static int vc4_hdmi_debugfs_regs(struct seq_file *m, void *unused) drm_print_regset32(&p, &vc4_hdmi->ram_regset); drm_print_regset32(&p, &vc4_hdmi->rm_regset); + pm_runtime_put(&vc4_hdmi->pdev->dev); + drm_dev_exit(idx); return 0; -- 2.43.0