From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELtjyW+9A9hx6uqAh0rryBhaq6f62VPvDluFF/EsHPG0m0U51KGswJbw5MJOwHNocyQV9HzP ARC-Seal: i=1; a=rsa-sha256; t=1520954908; cv=none; d=google.com; s=arc-20160816; b=ouPmrG99J3j8YyKA2j0WD9IzZix+K1j4yk+0zi5uuIRPJKJOjVMFPmkoTCGT7hMSad /yN5ZprjLpSohYjq+S95uUV76Q8TBN6qmV70PUwGuAibzmI8CjLZGWDSJ4MKRkX5RVtx CZtNr0a7y5V+WQJ+qtNyboUuzX7N6BNSoG73j3cR8OYfDdVSStixLGfgZ+mLzNyRH8l8 xjdHMalqz/MthDFkDGuw2D9IC/grtM6MeBgxmt7p2S8tUS1pBEV5TRPPnCd/YKidKGB2 xuYvQ45pU5Quy4yxSpKj5jochcZ0eL0KZWAAOYDa2n7TuxzoYlaQ9+glWCfAQFMN/Z/e DtKQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=wH01SY+iYBQBB3BXffoXDJ8LR7Y6GNixB8zs0cNQIpM=; b=rObmJGKBbyoQGazYa04pngBE62NOT2rfmASdME80fkHLLDr2dYyTq09lIT6Y/5My+V O0zC7gXZ2QJZ6pt8Hw3qHw+bBuFF7HFpK+QPFSQfBb7sRPBi73Yxuh1mOS575J+J+SPJ rhgc2zZWf4FG2aVrhaSw0BkXTAttsZeizq34ODHarJSQyADko7Ci+EWtC+ivBcPVXjBo 4qu1sbfqK0WPpqhsXpHIZnDYzoaS+qyzjomod5mS1ZUBVf0isD6PnTNk+3+lK3yNYRIQ TpBPGJSvutE5KJ5JaEq3LYwEqGnbTxwaE9hQobp5nwn7z6BNE6WdYMFjDedoTA4H7Omu ml7g== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.71.90 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.71.90 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alex Deucher , Mike Lothian , Lyude Paul , Lukas Wunner Subject: [PATCH 4.15 024/146] drm/amdgpu: Fix deadlock on runtime suspend Date: Tue, 13 Mar 2018 16:23:11 +0100 Message-Id: <20180313152322.323324350@linuxfoundation.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180313152320.439085687@linuxfoundation.org> References: <20180313152320.439085687@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1594836813269869627?= X-GMAIL-MSGID: =?utf-8?q?1594836813269869627?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Lukas Wunner commit aa0aad57909eb321746325951d66af88a83bc956 upstream. amdgpu's ->runtime_suspend hook calls drm_kms_helper_poll_disable(), which waits for the output poll worker to finish if it's running. The output poll worker meanwhile calls pm_runtime_get_sync() in amdgpu's ->detect hooks, which waits for the ongoing suspend to finish, causing a deadlock. Fix by not acquiring a runtime PM ref if the ->detect hooks are called in the output poll worker's context. This is safe because the poll worker is only enabled while runtime active and we know that ->runtime_suspend waits for it to finish. Fixes: d38ceaf99ed0 ("drm/amdgpu: add core driver (v4)") Cc: stable@vger.kernel.org # v4.2+: 27d4ee03078a: workqueue: Allow retrieval of current task's work struct Cc: stable@vger.kernel.org # v4.2+: 25c058ccaf2e: drm: Allow determining if current task is output poll worker Cc: Alex Deucher Tested-by: Mike Lothian Reviewed-by: Lyude Paul Signed-off-by: Lukas Wunner Link: https://patchwork.freedesktop.org/patch/msgid/4c9bf72aacae1eef062bd134cd112e0770a7f121.1518338789.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c | 58 ++++++++++++++++--------- 1 file changed, 38 insertions(+), 20 deletions(-) --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c @@ -737,9 +737,11 @@ amdgpu_connector_lvds_detect(struct drm_ enum drm_connector_status ret = connector_status_disconnected; int r; - r = pm_runtime_get_sync(connector->dev->dev); - if (r < 0) - return connector_status_disconnected; + if (!drm_kms_helper_is_poll_worker()) { + r = pm_runtime_get_sync(connector->dev->dev); + if (r < 0) + return connector_status_disconnected; + } if (encoder) { struct amdgpu_encoder *amdgpu_encoder = to_amdgpu_encoder(encoder); @@ -758,8 +760,12 @@ amdgpu_connector_lvds_detect(struct drm_ /* check acpi lid status ??? */ amdgpu_connector_update_scratch_regs(connector, ret); - pm_runtime_mark_last_busy(connector->dev->dev); - pm_runtime_put_autosuspend(connector->dev->dev); + + if (!drm_kms_helper_is_poll_worker()) { + pm_runtime_mark_last_busy(connector->dev->dev); + pm_runtime_put_autosuspend(connector->dev->dev); + } + return ret; } @@ -869,9 +875,11 @@ amdgpu_connector_vga_detect(struct drm_c enum drm_connector_status ret = connector_status_disconnected; int r; - r = pm_runtime_get_sync(connector->dev->dev); - if (r < 0) - return connector_status_disconnected; + if (!drm_kms_helper_is_poll_worker()) { + r = pm_runtime_get_sync(connector->dev->dev); + if (r < 0) + return connector_status_disconnected; + } encoder = amdgpu_connector_best_single_encoder(connector); if (!encoder) @@ -925,8 +933,10 @@ amdgpu_connector_vga_detect(struct drm_c amdgpu_connector_update_scratch_regs(connector, ret); out: - pm_runtime_mark_last_busy(connector->dev->dev); - pm_runtime_put_autosuspend(connector->dev->dev); + if (!drm_kms_helper_is_poll_worker()) { + pm_runtime_mark_last_busy(connector->dev->dev); + pm_runtime_put_autosuspend(connector->dev->dev); + } return ret; } @@ -989,9 +999,11 @@ amdgpu_connector_dvi_detect(struct drm_c enum drm_connector_status ret = connector_status_disconnected; bool dret = false, broken_edid = false; - r = pm_runtime_get_sync(connector->dev->dev); - if (r < 0) - return connector_status_disconnected; + if (!drm_kms_helper_is_poll_worker()) { + r = pm_runtime_get_sync(connector->dev->dev); + if (r < 0) + return connector_status_disconnected; + } if (!force && amdgpu_connector_check_hpd_status_unchanged(connector)) { ret = connector->status; @@ -1116,8 +1128,10 @@ out: amdgpu_connector_update_scratch_regs(connector, ret); exit: - pm_runtime_mark_last_busy(connector->dev->dev); - pm_runtime_put_autosuspend(connector->dev->dev); + if (!drm_kms_helper_is_poll_worker()) { + pm_runtime_mark_last_busy(connector->dev->dev); + pm_runtime_put_autosuspend(connector->dev->dev); + } return ret; } @@ -1360,9 +1374,11 @@ amdgpu_connector_dp_detect(struct drm_co struct drm_encoder *encoder = amdgpu_connector_best_single_encoder(connector); int r; - r = pm_runtime_get_sync(connector->dev->dev); - if (r < 0) - return connector_status_disconnected; + if (!drm_kms_helper_is_poll_worker()) { + r = pm_runtime_get_sync(connector->dev->dev); + if (r < 0) + return connector_status_disconnected; + } if (!force && amdgpu_connector_check_hpd_status_unchanged(connector)) { ret = connector->status; @@ -1430,8 +1446,10 @@ amdgpu_connector_dp_detect(struct drm_co amdgpu_connector_update_scratch_regs(connector, ret); out: - pm_runtime_mark_last_busy(connector->dev->dev); - pm_runtime_put_autosuspend(connector->dev->dev); + if (!drm_kms_helper_is_poll_worker()) { + pm_runtime_mark_last_busy(connector->dev->dev); + pm_runtime_put_autosuspend(connector->dev->dev); + } return ret; }