Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <dc41915d-4cd8-857f-8f2b-78e821ab9ab1@amd.com>
Date:   Tue, 29 Mar 2022 10:46:25 -0400
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101
 Thunderbird/91.7.0
Subject: Re: [PATCH] UPSTREAM: drm/amdgpu: Disable ABM when AC mode
Content-Language: en-US
From:   Harry Wentland <harry.wentland@amd.com>
To:     Ryan Lin <tsung-hua.lin@amd.com>, sunpeng.li@amd.com,
        alexander.deucher@amd.com, christian.koenig@amd.com,
        David1.Zhou@amd.com, airlied@linux.ie, daniel@ffwll.ch,
        seanpaul@chromium.org, bas@basnieuwenhuizen.nl,
        nicholas.kazlauskas@amd.com, sashal@kernel.org,
        markyacoub@google.com, victorchengchi.lu@amd.com,
        ching-shih.li@amd.corp-partner.google.com,
        Rodrigo.Siqueira@amd.com, ddavenport@chromium.org,
        amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
        linux-kernel@vger.kernel.org, leon.li@amd.com
References: <20220324231000.4072275-1-tsung-hua.lin@amd.com>
 <cd030261-6d49-263b-0018-4fc87cdf0958@amd.com>
In-Reply-To: <cd030261-6d49-263b-0018-4fc87cdf0958@amd.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?MGIzN3hyd3RuUjRvVHBYMUg2UXRYWEpCY3NNZ0NTdHkwNnk2em9WenlOTTZV?=
 =?utf-8?B?T2Fhb1JvcUlsN1l5WEZDQ21ITENTeExpNmZ3TzMyT01JZVlYTnBrTHNlNTVI?=
 =?utf-8?B?MXBqbG8rUC95cGhzcXg3TXp3SXBHMTUvZGF6Wm9ZMXlxT3ZoN3ZVcmozMEdw?=
 =?utf-8?B?aDBqaDJ6cE9kZ3VMRGhDdmV2V2JTOExWSkNxTU90T1VxdGVCMzVQYTNHQzdE?=
 =?utf-8?B?eTFnRDkxZ2hCSFYyUmhaMW9CTi8wMXRJRER4UUoxRG16MHNrL3ZubUFZQmxn?=
 =?utf-8?B?NUN2SHlUMlkzVFpNTVBrR1BZNEtjeEk4MzlhUU9vbzYwNjJ3ZC8rdHVHaTVv?=
 =?utf-8?B?NEkzdG9LQmJxSU9kaG9kUm9MWjFjeFBmRmd2dVBZdU5iYmhlZFZia2pQb2FH?=
 =?utf-8?B?anBOb2l1NkZFZDBFN2tMMTBQVUZnODdycHhDUFcrRGlsS0hsaG1uQU9jbVRK?=
 =?utf-8?B?WlJNUDRPL0dyOFNTelp3VlhRby9ySVVHQW9DcDhCMi95NHhDb1Y1emNwem9o?=
 =?utf-8?B?WEpMUFNYUm1Kblk3dk5YN1QyOXlrK0psK2RZaktOYnJWZXozS1FwQ01IV3d3?=
 =?utf-8?B?Yi91SjI3SDY2a0dUeS8zMEM2ZnlOaFI1NGJCY0xrVEdOT2dwb0NmTElxU3R1?=
 =?utf-8?B?aDN1cnI5akRsekwzand6R1Jsc0k2QWtSMkFzOEF2Q1dzTXVUVG5heHZxMGZw?=
 =?utf-8?B?L0Nxa09YeFpoOEZURHNTS1JVU29JSWhYaFdHRzlMeHVRcDFaUlcyQzRYUVBQ?=
 =?utf-8?B?dlN4dDNVUXdEbE9oSFlZNHBieEZNbFdYTGdXWWl4UzhoWlI0L0Y4TTBaaEJU?=
 =?utf-8?B?QzM3NUdJMGluVFBNVmpNMkhqSFRWZWc1UFdNVTBFUWZlcW1sZUhzMWRkZ3pT?=
 =?utf-8?B?VWZ2Ri9TUFJKRWQyZEE5anFwYVBWQmpIbUJRSExBQTNWWis0WmoyUVBacW01?=
 =?utf-8?B?ejZhT0l0RXBIc2lRZVhkVFU0TEVSNzUzbWlaM0I4YTQyVUVBOVhURFYvY29h?=
 =?utf-8?B?azBNUStMWm9wZVYxTlN3MzB4OG8wV1ZrNHBvR3I5Tlk0aEUrL0RRSG9ZS0Ns?=
 =?utf-8?B?Y2RqaExBeVByZzhHaklQNFcyRnRnUTc1VlhyQ2daVFl6VHFuMTgxNk9FS0h2?=
 =?utf-8?B?Q1R1ZVhhelQwYkNCaU8zNmRNUFJ3amNxaWZyVHh5U2tMdFZvNlBQQlJRcG5G?=
 =?utf-8?B?WS9tcmZZeHhmQ3NPcVYvdGxTbXhYMmtvTGxGVjB2aXpBSXA0NjhLdVRtK3Iv?=
 =?utf-8?B?Z2NYcDdmTmtwRHpjNGFaMjEzajNueXI4M3JERTk2akJzREtpZm5zM2hNbzM3?=
 =?utf-8?B?V05sbzBvaG1NOHVZOUdSbnlCZGV6cThGMENoaW9MaXhPNWh2ZjVIaU5PT3Bh?=
 =?utf-8?B?Rko1MThFVnJ2RnRzVnNURkNpeEVmTjJwWHdoQURVb2V0ZkZITW9KOWQrR1BH?=
 =?utf-8?B?YjlSWlE1WUwzc01GYjZvbVN4N1lJNlJtNzRIMUpxV2I0R1lsZk5rQVF1VFNO?=
 =?utf-8?B?MzN1L2hLTUd6NGRPeVNZTDVaeFgzUnZIN0EwZVp5QWE3SllZcnNObzloYXJt?=
 =?utf-8?B?SkFna3pSRUwwTDQya0xvQmVPbGhLUElsaC9OQnZDR0RVRlZOdUFpcTRmVzdC?=
 =?utf-8?B?bkQ1TUtGb3QwQk0vTjRBTktwN3daYXdyTGMyWmFzM0Z0VHhSb2FkSG9ab3E2?=
 =?utf-8?B?NksycStwbk81MnpaOGM5ZW9sbUcwZjJmYmppbHVPTEdjbVA1WUQ3cWlHMHUz?=
 =?utf-8?B?SzdsYk1uTU9VQnowWmFVV1JUVVpxTXYzSEhKcElVU1BGeHlrT1NLK1FnSkI0?=
 =?utf-8?B?Y3ErblRpRExrRHk2R0pMQjZxQUFscVFHd1M5RGxGV21pYjRBRmZURDZlRVRS?=
 =?utf-8?B?bzhjUUUxVkYyckFiallaL1Y3R2dtNWdpaGthUWFaV1NPVzFEYUZoYktySW01?=
 =?utf-8?B?aXVKcWtSKytkTWpCaWNTNGZJdjd1T1kxVHVEQ0JSMmRRekl0QWxjVnc0NldM?=
 =?utf-8?B?SFZnODgyNVdwakh0QTRuZ1IwazlOU3N4VXNUYmFkK3BuR3BQY21NKzcreUJN?=
 =?utf-8?B?TWlwRjAvR1FNVHpRTUlTSzRoMGdIeks4UFVObzRDeXBITkY4ZHNGZ1d1bmNR?=
 =?utf-8?B?R01HWEx1ZnhmbkpCK2hjV1F0bFpQOW1kU1QyZFNXWHg1aEw1TUF2NjkxM0d2?=
 =?utf-8?B?cncxemoycDkrcHI1VWdPeG5tV0FiSWQ4b1V0Z2tjS1VYeU9WaXF3MkJOaWg3?=
 =?utf-8?B?ZW9JeERhOVZNVFRaTklCbW1INzNucTByZGRxQVN6czNmdjg3VW10UW1xOVpC?=
 =?utf-8?B?WHBVRWozSGNwM0hsV0xZR3lNeEwxYkdja1lZcTBTK3pGUmFqSnU3dz09?=
X-OriginatorOrg: amd.com
X-MS-Exchange-CrossTenant-Network-Message-Id: c138e329-9ffd-4795-75b4-08da1192e93c
X-MS-Exchange-CrossTenant-AuthSource: CO6PR12MB5427.namprd12.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 29 Mar 2022 14:46:30.4941
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: Ams0W536QQRoSvJPKs3NxdRarAz4tXUIPIXpKAtQNZ2YpNtFmxhrL/bzs5yvF0bdhTxSXDBlPK60RE5Fj1zDKA==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: MN2PR12MB3821
X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED,
        DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,NICE_REPLY_A,RCVD_IN_DNSWL_NONE,
        RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_PASS,T_SCC_BODY_TEXT_LINE
        autolearn=ham autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org


On 2022-03-29 10:33, Harry Wentland wrote:
> 
> 
> On 2022-03-24 19:10, Ryan Lin wrote:
>> Disable ABM feature when the system is running on AC mode to get
>> the more perfect contrast of the display.
>>
>> Signed-off-by: Ryan Lin <tsung-hua.lin@amd.com>
>>
>> ---
>>  drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c      |  4 ++
>>  drivers/gpu/drm/amd/amdgpu/amdgpu_device.c    |  1 +
>>  drivers/gpu/drm/amd/display/dc/dce/dmub_abm.c | 58 ++++++++++++-------
>>  drivers/gpu/drm/amd/pm/inc/amdgpu_dpm.h       |  1 +
>>  4 files changed, 42 insertions(+), 22 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c
>> index c560c1ab62ecb..bc8bb9aad2e36 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c
>> @@ -822,6 +822,10 @@ static int amdgpu_acpi_event(struct notifier_block *nb,
>>  	struct amdgpu_device *adev = container_of(nb, struct amdgpu_device, acpi_nb);
>>  	struct acpi_bus_event *entry = (struct acpi_bus_event *)data;
>>  
>> +	if (strcmp(entry->device_class, "battery") == 0) {
>> +		adev->pm.ac_power = power_supply_is_system_supplied() > 0;
>> +	}
>> +
>>  	if (strcmp(entry->device_class, ACPI_AC_CLASS) == 0) {
>>  		if (power_supply_is_system_supplied() > 0)
>>  			DRM_DEBUG_DRIVER("pm: AC\n");
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>> index abfcc1304ba0c..3a0afe7602727 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>> @@ -3454,6 +3454,7 @@ int amdgpu_device_init(struct amdgpu_device *adev,
>>  
>>  	adev->gfx.gfx_off_req_count = 1;
>>  	adev->pm.ac_power = power_supply_is_system_supplied() > 0;
>> +	adev->pm.old_ac_power = true;
>>  
>>  	atomic_set(&adev->throttling_logging_enabled, 1);
>>  	/*
>> diff --git a/drivers/gpu/drm/amd/display/dc/dce/dmub_abm.c b/drivers/gpu/drm/amd/display/dc/dce/dmub_abm.c
>> index 54a1408c8015c..478a734b66926 100644
>> --- a/drivers/gpu/drm/amd/display/dc/dce/dmub_abm.c
>> +++ b/drivers/gpu/drm/amd/display/dc/dce/dmub_abm.c
>> @@ -23,6 +23,8 @@
>>   *
>>   */
>>  
>> +#include <linux/power_supply.h>
>> +#include "amdgpu.h"
>>  #include "dmub_abm.h"
>>  #include "dce_abm.h"
>>  #include "dc.h"
>> @@ -51,6 +53,7 @@
>>  #define DISABLE_ABM_IMMEDIATELY 255
>>  
>>  
>> +extern uint amdgpu_dm_abm_level;
>>  
>>  static void dmub_abm_enable_fractional_pwm(struct dc_context *dc)
>>  {
>> @@ -117,28 +120,6 @@ static void dmub_abm_init(struct abm *abm, uint32_t backlight)
>>  	dmub_abm_enable_fractional_pwm(abm->ctx);
>>  }
>>  
>> -static unsigned int dmub_abm_get_current_backlight(struct abm *abm)
>> -{
>> -	struct dce_abm *dce_abm = TO_DMUB_ABM(abm);
>> -	unsigned int backlight = REG_READ(BL1_PWM_CURRENT_ABM_LEVEL);
>> -
>> -	/* return backlight in hardware format which is unsigned 17 bits, with
>> -	 * 1 bit integer and 16 bit fractional
>> -	 */
>> -	return backlight;
>> -}
>> -
>> -static unsigned int dmub_abm_get_target_backlight(struct abm *abm)
>> -{
>> -	struct dce_abm *dce_abm = TO_DMUB_ABM(abm);
>> -	unsigned int backlight = REG_READ(BL1_PWM_TARGET_ABM_LEVEL);
>> -
>> -	/* return backlight in hardware format which is unsigned 17 bits, with
>> -	 * 1 bit integer and 16 bit fractional
>> -	 */
>> -	return backlight;
>> -}
>> -
>>  static bool dmub_abm_set_level(struct abm *abm, uint32_t level)
>>  {
>>  	union dmub_rb_cmd cmd;
>> @@ -148,6 +129,9 @@ static bool dmub_abm_set_level(struct abm *abm, uint32_t level)
>>  	int edp_num;
>>  	uint8_t panel_mask = 0;
>>  
>> +	if (power_supply_is_system_supplied() > 0)
>> +		level = 0;
>> +
>>  	get_edp_links(dc->dc, edp_links, &edp_num);
>>  
>>  	for (i = 0; i < edp_num; i++) {
>> @@ -170,6 +154,36 @@ static bool dmub_abm_set_level(struct abm *abm, uint32_t level)
>>  	return true;
>>  }
>>  
>> +static unsigned int dmub_abm_get_current_backlight(struct abm *abm)
>> +{
>> +	struct dce_abm *dce_abm = TO_DMUB_ABM(abm);
>> +	unsigned int backlight = REG_READ(BL1_PWM_CURRENT_ABM_LEVEL);
>> +	struct dc_context *dc = abm->ctx;
>> +	struct amdgpu_device *adev = dc->driver_context;
>> +
>> +	if (adev->pm.ac_power != adev->pm.old_ac_power) {
> 
> This patch still has the problem of accessing adev from within DC.
> That'll break things on other platforms. This information needs to
> come in through the DC interface if we want to enable/disable ABM in
> this function.
> 
> After a closer look I also don't think that amdgpu is the right place
> to control the logic to disable ABM in AC mode, i.e. to switch between
> ABM levels. Take a look at dm_connector_state.abm_level and the
> abm_level_property. It's exposed to userspace as "abm level".
> 
> The "abm level" defaults to "0" unless userspace sets the "abm level"
> to something else. The same component that sets the "abm level"
> initially is the one that should set it to "0" when in AC mode.
> 

It might be that the ABM level is controlled via the abmlevel module
parameter. If that's the case and there isn't a userspace that sets the
"abm level" property then the easiest way to handle this is to switch
between 0 and amdgpu_dm_abm_level inside amdgpu_dm when there is a
AC/DC switch. Either way we shouldn't need to change DC.

Harry

> Harry
> 
>> +		dmub_abm_set_level(abm, amdgpu_dm_abm_level);
>> +		adev->pm.ac_power = power_supply_is_system_supplied() > 0;
>> +		adev->pm.old_ac_power = adev->pm.ac_power;
>> +	}
>> +
>> +	/* return backlight in hardware format which is unsigned 17 bits, with
>> +	 * 1 bit integer and 16 bit fractional
>> +	 */
>> +	return backlight;
>> +}
>> +
>> +static unsigned int dmub_abm_get_target_backlight(struct abm *abm)
>> +{
>> +	struct dce_abm *dce_abm = TO_DMUB_ABM(abm);
>> +	unsigned int backlight = REG_READ(BL1_PWM_TARGET_ABM_LEVEL);
>> +
>> +	/* return backlight in hardware format which is unsigned 17 bits, with
>> +	 * 1 bit integer and 16 bit fractional
>> +	 */
>> +	return backlight;
>> +}
>> +
>>  static bool dmub_abm_init_config(struct abm *abm,
>>  	const char *src,
>>  	unsigned int bytes,
>> diff --git a/drivers/gpu/drm/amd/pm/inc/amdgpu_dpm.h b/drivers/gpu/drm/amd/pm/inc/amdgpu_dpm.h
>> index f6e0e7d8a0077..de459411a0e83 100644
>> --- a/drivers/gpu/drm/amd/pm/inc/amdgpu_dpm.h
>> +++ b/drivers/gpu/drm/amd/pm/inc/amdgpu_dpm.h
>> @@ -445,6 +445,7 @@ struct amdgpu_pm {
>>  	uint32_t                smu_prv_buffer_size;
>>  	struct amdgpu_bo        *smu_prv_buffer;
>>  	bool ac_power;
>> +	bool old_ac_power;
>>  	/* powerplay feature */
>>  	uint32_t pp_feature;
>>  
>