From patchwork Mon Jan 23 21:09:57 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans de Goede X-Patchwork-Id: 718778 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3v6kW72vWFz9rxl for ; Tue, 24 Jan 2017 08:10:59 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751083AbdAWVK6 (ORCPT ); Mon, 23 Jan 2017 16:10:58 -0500 Received: from mx1.redhat.com ([209.132.183.28]:36766 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751369AbdAWVKj (ORCPT ); Mon, 23 Jan 2017 16:10:39 -0500 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 917E9C057FA6; Mon, 23 Jan 2017 21:10:39 +0000 (UTC) Received: from shalem.localdomain.com (ovpn-116-98.ams2.redhat.com [10.36.116.98]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id v0NLA0eg025633; Mon, 23 Jan 2017 16:10:36 -0500 From: Hans de Goede To: Daniel Vetter , Jani Nikula , =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= , Jarkko Nikula , Wolfram Sang , Len Brown , Andy Shevchenko , Thomas Gleixner , "H . Peter Anvin" Cc: Hans de Goede , intel-gfx , dri-devel@lists.freedesktop.org, Mika Westerberg , Takashi Iwai , "russianneuromancer @ ya . ru" , linux-i2c@vger.kernel.org Subject: [PATCH v2 12/13] drm/i915: Listen for PMIC bus access notifications Date: Mon, 23 Jan 2017 22:09:57 +0100 Message-Id: <20170123210958.18410-13-hdegoede@redhat.com> In-Reply-To: <20170123210958.18410-1-hdegoede@redhat.com> References: <20170123210958.18410-1-hdegoede@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Mon, 23 Jan 2017 21:10:40 +0000 (UTC) Sender: linux-i2c-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org Listen for PMIC bus access notifications and get FORCEWAKE_ALL while the bus is accessed to avoid needing to do any forcewakes, which need PMIC bus access, while the PMIC bus is busy: This fixes errors like these showing up in dmesg, usually followed by a gfx or system freeze: [drm:fw_domains_get [i915]] *ERROR* render: timed out waiting for forcewake ack request. [drm:fw_domains_get [i915]] *MEDIA* render: timed out waiting for forcewake ack request. i2c_designware 808622C1:06: punit semaphore timed out, resetting i2c_designware 808622C1:06: PUNIT SEM: 2 i2c_designware 808622C1:06: couldn't acquire bus ownership Downside of this approach is that it causes wakeups whenever the PMIC bus is accessed. Unfortunately we cannot simply wait for the PMIC bus to go idle when we hit a race, as forcewakes may be done from interrupt handlers where we cannot sleep to wait for the i2c PMIC bus access to finish. Note that the notifications and thus the wakeups will only happen on baytrail / cherrytrail devices using PMICs with a shared i2c bus for P-Unit and host PMIC access (i2c busses with a _SEM method in their APCI node), e.g. an axp288 PMIC. I plan to write some patches for drivers accessing the PMIC bus to limit their bus accesses to a bare minimum (e.g. cache registers, do not update battery level more often then 4 times a minute), to limit the amount of wakeups. BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=155241 Signed-off-by: Hans de Goede Tested-by: tagorereddy --- Changes in v2: -Spelling: P-Unit, PMIC --- drivers/gpu/drm/i915/i915_drv.h | 1 + drivers/gpu/drm/i915/intel_uncore.c | 35 +++++++++++++++++++++++++++++++++++ 2 files changed, 36 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index c717329..52f7dde 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -721,6 +721,7 @@ struct intel_uncore { const struct intel_forcewake_range *fw_domains_table; unsigned int fw_domains_table_entries; + struct notifier_block pmic_bus_access_nb; struct intel_uncore_funcs funcs; unsigned fifo_count; diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c index 3767307..175fe02 100644 --- a/drivers/gpu/drm/i915/intel_uncore.c +++ b/drivers/gpu/drm/i915/intel_uncore.c @@ -25,6 +25,7 @@ #include "intel_drv.h" #include "i915_vgpu.h" +#include #include #define FORCEWAKE_ACK_TIMEOUT_MS 50 @@ -429,12 +430,16 @@ static void __intel_uncore_early_sanitize(struct drm_i915_private *dev_priv, void intel_uncore_suspend(struct drm_i915_private *dev_priv) { + iosf_mbi_unregister_pmic_bus_access_notifier( + &dev_priv->uncore.pmic_bus_access_nb); __intel_uncore_forcewake_reset(dev_priv, false); } void intel_uncore_resume(struct drm_i915_private *dev_priv) { __intel_uncore_early_sanitize(dev_priv, true); + iosf_mbi_register_pmic_bus_access_notifier( + &dev_priv->uncore.pmic_bus_access_nb); i915_check_and_clear_faults(dev_priv); } @@ -1390,6 +1395,28 @@ static void intel_uncore_fw_domains_init(struct drm_i915_private *dev_priv) dev_priv->uncore.fw_domains_table_entries = ARRAY_SIZE((d)); \ } +static int i915_pmic_bus_access_notifier(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct drm_i915_private *dev_priv = container_of(nb, + struct drm_i915_private, uncore.pmic_bus_access_nb); + + switch (action) { + case MBI_PMIC_BUS_ACCESS_BEGIN: + /* + * forcewake all to make sure that we don't need to forcewake + * any power-planes while the pmic bus is busy. + */ + intel_uncore_forcewake_get(dev_priv, FORCEWAKE_ALL); + break; + case MBI_PMIC_BUS_ACCESS_END: + intel_uncore_forcewake_put(dev_priv, FORCEWAKE_ALL); + break; + } + + return NOTIFY_OK; +} + void intel_uncore_init(struct drm_i915_private *dev_priv) { i915_check_vgpu(dev_priv); @@ -1399,6 +1426,8 @@ void intel_uncore_init(struct drm_i915_private *dev_priv) __intel_uncore_early_sanitize(dev_priv, false); dev_priv->uncore.unclaimed_mmio_check = 1; + dev_priv->uncore.pmic_bus_access_nb.notifier_call = + i915_pmic_bus_access_notifier; switch (INTEL_INFO(dev_priv)->gen) { default: @@ -1458,6 +1487,9 @@ void intel_uncore_init(struct drm_i915_private *dev_priv) ASSIGN_READ_MMIO_VFUNCS(vgpu); } + iosf_mbi_register_pmic_bus_access_notifier( + &dev_priv->uncore.pmic_bus_access_nb); + i915_check_and_clear_faults(dev_priv); } #undef ASSIGN_WRITE_MMIO_VFUNCS @@ -1465,6 +1497,9 @@ void intel_uncore_init(struct drm_i915_private *dev_priv) void intel_uncore_fini(struct drm_i915_private *dev_priv) { + iosf_mbi_unregister_pmic_bus_access_notifier( + &dev_priv->uncore.pmic_bus_access_nb); + /* Paranoia: make sure we have disabled everything before we exit. */ intel_uncore_sanitize(dev_priv); __intel_uncore_forcewake_reset(dev_priv, false);