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From: javier.martinez@collabora•co.uk (Javier Martinez Canillas)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v3 00/19] Exynos SYSMMU (IOMMU) integration with DT and DMA-mapping subsystem
Date: Wed, 14 Jan 2015 01:19:02 +0100	[thread overview]
Message-ID: <54B5B5F6.3030607@collabora.co.uk> (raw)
In-Reply-To: <54B4ABFB.5000501@samsung.com>

Hello Joonyoung,

On 01/13/2015 06:24 AM, Joonyoung Shim wrote:
>> 
>> Yes, I was not able to trigger that by running modetest but by turning off
>> my HDMI monitor and then turning it on again. When the monitor is turned
>> on then I see a "Power domain power-domain disable failed" and the imprecise
>> external abort error.
>> 
>> I had to disable CONFIG_DRM_EXYNOS_DP in order to trigger though and that
>> is why I was not able to reproduce it before.
>> 
>> I think though that this is a separate issue of the HDMI not working since
>> power domains should be able to have many consumers devices and I see that
>> other power domains are used that way.
>> 
> 
> OK, we need more investigation.
>

I dug further on this issue and found that the cause is that the exynos_mixer
driver needs some clocks (CLK_HDMI and CLK_SCLK_HDMI) grabbed by exynos_hdmi
to be kept enabled after hdmi_poweroff (drivers/gpu/drm/exynos/exynos_hdmi.c).

Otherwise, any access to mixer device registers leads to an imprecise external
abort error. The following change [0] to the Exynos DRM HDMI driver makes the
issue to not happen and I can successfully execute:

# echo 1 > /sys/devices/platform/exynos-drm/graphics/fb0/blank
# echo 0 > /sys/devices/platform/exynos-drm/graphics/fb0/blank

Only not disabling the hdmi clock [1]: is enough but doing so makes sometimes the
DISP1 power domain disabling fails. It doesn't seem to have side effect though
since I also see the signal in the HDMI display to go standby and then on again.

# echo 0 > /sys/devices/platform/exynos-drm/graphics/fb0/blank
# echo 1 > /sys/devices/platform/exynos-drm/graphics/fb0/blank
[   63.089080] Power domain disp1-power-domain disable failed
# echo 0 > /sys/devices/platform/exynos-drm/graphics/fb0/blank
#

That error message when both clocks are not disabled on hdmi_poweroff() though.

I tried different things like set parent of mixer clock to hdmi clock instead
of aclk200_disp1 or make the Exynos DRM mixer driver to grab the hdmi clock
from  DT and prepare_enable from mixer_poweron() but in all cases the same
imprecise external abort error was triggered by mixer_poweron() trying to access
the mixer registers.

Any ideas?

Thanks a lot and best regards,
Javier

[0]:
diff --git a/drivers/gpu/drm/exynos/exynos_hdmi.c b/drivers/gpu/drm/exynos/exynos_hdmi.c
index 5765a161abdd..0887911cfdd5 100644
--- a/drivers/gpu/drm/exynos/exynos_hdmi.c
+++ b/drivers/gpu/drm/exynos/exynos_hdmi.c
@@ -2084,8 +2084,8 @@ static void hdmi_poweroff(struct exynos_drm_display *display)
 
        cancel_delayed_work(&hdata->hotplug_work);
 
-       clk_disable_unprepare(res->sclk_hdmi);
-       clk_disable_unprepare(res->hdmi);
 
        /* reset pmu hdmiphy control bit to disable hdmiphy */
        regmap_update_bits(hdata->pmureg, PMU_HDMI_PHY_CONTROL,


[1]:
diff --git a/drivers/gpu/drm/exynos/exynos_hdmi.c b/drivers/gpu/drm/exynos/exynos_hdmi.c
index 5765a161abdd..628bff96d543 100644
--- a/drivers/gpu/drm/exynos/exynos_hdmi.c
+++ b/drivers/gpu/drm/exynos/exynos_hdmi.c
@@ -2085,7 +2085,7 @@ static void hdmi_poweroff(struct exynos_drm_display *display)
        cancel_delayed_work(&hdata->hotplug_work);
 
        clk_disable_unprepare(res->sclk_hdmi);
-       clk_disable_unprepare(res->hdmi);
 
        /* reset pmu hdmiphy control bit to disable hdmiphy */
        regmap_update_bits(hdata->pmureg, PMU_HDMI_PHY_CONTROL,

  parent reply	other threads:[~2015-01-14  0:19 UTC|newest]

Thread overview: 63+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-11-19 11:15 [PATCH v3 00/19] Exynos SYSMMU (IOMMU) integration with DT and DMA-mapping subsystem Marek Szyprowski
2014-11-19 11:15 ` [PATCH v3 01/19] iommu: fix const qualifier in of_iommu_set_ops Marek Szyprowski
2014-11-19 11:15 ` [PATCH v3 02/19] iommu: fix initialization without 'add_device' callback Marek Szyprowski
2014-11-19 11:15 ` [PATCH v3 03/19] arm: dma-mapping: add missing check for iommu Marek Szyprowski
2014-11-19 11:15 ` [PATCH v3 04/19] drm: exynos: detach from default dma-mapping domain on init Marek Szyprowski
2014-11-19 11:15 ` [PATCH v3 05/19] arm: exynos: pm_domains: add support for devices registered before arch_initcall Marek Szyprowski
2014-11-19 11:15 ` [PATCH v3 06/19] ARM: dts: exynos4: add sysmmu nodes Marek Szyprowski
2014-11-19 11:15 ` [PATCH v3 07/19] iommu: exynos: don't read version register on every tlb operation Marek Szyprowski
2014-11-19 11:15 ` [PATCH v3 08/19] iommu: exynos: remove unused functions Marek Szyprowski
2014-11-19 11:15 ` [PATCH v3 09/19] iommu: exynos: remove useless spinlock Marek Szyprowski
2014-11-19 11:15 ` [PATCH v3 10/19] iommu: exynos: refactor function parameters to simplify code Marek Szyprowski
2014-11-19 11:15 ` [PATCH v3 11/19] iommu: exynos: remove unused functions, part 2 Marek Szyprowski
2014-11-19 11:15 ` [PATCH v3 12/19] iommu: exynos: remove useless device_add/remove callbacks Marek Szyprowski
2014-11-19 11:15 ` [PATCH v3 13/19] iommu: exynos: add support for binding more than one sysmmu to master device Marek Szyprowski
2014-11-19 11:15 ` [PATCH v3 14/19] iommu: exynos: add support for runtime_pm Marek Szyprowski
2014-11-19 11:15 ` [PATCH v3 15/19] iommu: exynos: rename variables to reflect their purpose Marek Szyprowski
2014-11-19 11:15 ` [PATCH v3 16/19] iommu: exynos: document internal structures Marek Szyprowski
2014-11-19 11:15 ` [PATCH v3 17/19] iommu: exynos: remove excessive includes and sort others alphabetically Marek Szyprowski
2014-11-19 11:15 ` [PATCH v3 18/19] iommu: exynos: init from dt-specific callback instead of initcall Marek Szyprowski
2014-12-14 12:45   ` Laurent Pinchart
2014-12-15  9:47     ` Thierry Reding
2014-12-15 17:17     ` Will Deacon
2014-12-15 17:27       ` Laurent Pinchart
2014-12-15 17:43         ` Will Deacon
2014-12-15 17:53           ` Laurent Pinchart
2014-12-15 18:13             ` Will Deacon
2014-12-15 18:19               ` Laurent Pinchart
2014-12-16 10:58                 ` Marek Szyprowski
2014-12-16 11:40               ` Arnd Bergmann
2014-12-16 12:07                 ` Laurent Pinchart
2014-12-16 12:10                   ` [Linaro-mm-sig] " Arnd Bergmann
2014-12-16 23:24                     ` Laurent Pinchart
2014-12-17 14:27                       ` Arnd Bergmann
2014-12-17 14:39                         ` Laurent Pinchart
2014-12-17 15:41                           ` Arnd Bergmann
2014-12-17 16:02                             ` Laurent Pinchart
2014-12-17 21:58                               ` Arnd Bergmann
2014-12-17 22:38                                 ` Laurent Pinchart
2014-12-17 14:53                         ` Lucas Stach
2014-12-17 15:56                           ` Arnd Bergmann
2014-12-18 20:36                             ` Laurent Pinchart
2014-12-18 23:21                               ` Arnd Bergmann
2014-11-19 11:15 ` [PATCH v3 19/19] iommu: exynos: add callback for initializing devices from device tree Marek Szyprowski
2014-12-02  9:59 ` [PATCH v3 00/19] Exynos SYSMMU (IOMMU) integration with DT and DMA-mapping subsystem Sjoerd Simons
2014-12-05 10:22   ` Marek Szyprowski
2015-01-06  9:49     ` Javier Martinez Canillas
2015-01-07  2:03       ` Joonyoung Shim
2015-01-07  9:33         ` Javier Martinez Canillas
2015-01-07  9:55           ` Joonyoung Shim
2015-01-08 16:42             ` Javier Martinez Canillas
2015-01-12  6:40               ` Joonyoung Shim
2015-01-12  9:43                 ` Joonyoung Shim
2015-01-12 16:09                 ` Javier Martinez Canillas
2015-01-13  5:24                   ` Joonyoung Shim
2015-01-13  8:40                     ` Joonyoung Shim
2015-01-13  9:43                       ` Javier Martinez Canillas
2015-01-13  9:21                     ` Javier Martinez Canillas
2015-01-14  0:19                     ` Javier Martinez Canillas [this message]
2015-01-14  0:24                       ` Javier Martinez Canillas
2015-01-20 11:12                         ` Joonyoung Shim
2015-01-20 14:05                           ` Javier Martinez Canillas
2015-01-16 10:33   ` Marek Szyprowski
2015-01-16 15:44     ` Sjoerd Simons

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