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Message-Id: <2YU3IR.4394CFYXZPEZ1@gmail.com>
Date: Mon, 12 Sep 2022 18:25:14 +0200
From: Matthieu CHARETTE <matthieu.charette@...il.com>
To: Jani Nikula <jani.nikula@...ux.intel.com>
Cc: lkp@...el.com, kbuild-all@...ts.01.org, tzimmermann@...e.de,
airlied@...ux.ie, linux-kernel@...r.kernel.org,
dri-devel@...ts.freedesktop.org, andrealmeid@...lia.com
Subject: Re: [PATCH] drm: Fix EDID firmware load on resume
Hi,
Sorry for late reply.
How do you propose to go then?
Can we still use a persistent platform device to load the firmware and
cache it? But, in this case the system will still crash in case the
user change drm.edid_firmware then, without replugging the device, he
suspends and resumes the machine.
Or you may have a better idea?
Thanks,
Matthieu
On Mon, Aug 8 2022 at 08:19:01 PM +0300, Jani Nikula
<jani.nikula@...ux.intel.com> wrote:
> On Mon, 08 Aug 2022, Matthieu CHARETTE <matthieu.charette@...il.com>
> wrote:
>> Sorry, What do you mean?
>
> You cache with one name at connector init time, but the name specified
> using drm.edid_firmware may be changed whenever, to cause the next
> EDID
> read to use a different EDID firmware.
>
> BR,
> Jani.
>
>
>>
>> Matthieu
>>
>> On Tue, Aug 2 2022 at 05:29:12 PM +0300, Jani Nikula
>> <jani.nikula@...ux.intel.com> wrote:
>>> On Wed, 27 Jul 2022, Matthieu CHARETTE <matthieu.charette@...il.com
>>> <mailto:matthieu.charette@...il.com>> wrote:
>>>> Loading an EDID using drm.edid_firmware parameter makes resume to
>>>> fail
>>>> after firmware cache is being cleaned. This is because
>>>> edid_load()
>>>> use a
>>>> temporary device to request the firmware. This cause the EDID
>>>> firmware
>>>> not to be cached from suspend. And, requesting the EDID firmware
>>>> return
>>>> an error during resume.
>>>> So the request_firmware() call should use a permanent device for
>>>> each
>>>> connector. Also, we should cache the EDID even if no monitor is
>>>> connected, in case it's plugged while suspended.
>>>
>>> AFAICT this breaks changing drm.edid_firmware runtime.
>>>
>>> BR,
>>> Jani.
>>>
>>>>
>>>> Link: <https://gitlab.freedesktop.org/drm/amd/-/issues/2061>
>>>> Signed-off-by: Matthieu CHARETTE <matthieu.charette@...il.com
>>>> <mailto:matthieu.charette@...il.com>>
>>>> ---
>>>> drivers/gpu/drm/drm_connector.c | 9 ++++
>>>> drivers/gpu/drm/drm_edid_load.c | 81
>>>> ++++++++++++++++++++++++++++-----
>>>> include/drm/drm_connector.h | 12 +++++
>>>> include/drm/drm_edid.h | 3 ++
>>>> 4 files changed, 94 insertions(+), 11 deletions(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/drm_connector.c
>>>> b/drivers/gpu/drm/drm_connector.c
>>>> index 1c48d162c77e..e8819ebf1c4b 100644
>>>> --- a/drivers/gpu/drm/drm_connector.c
>>>> +++ b/drivers/gpu/drm/drm_connector.c
>>>> @@ -31,6 +31,7 @@
>>>> #include <drm/drm_privacy_screen_consumer.h>
>>>> #include <drm/drm_sysfs.h>
>>>>
>>>> +#include <linux/platform_device.h>
>>>> #include <linux/uaccess.h>
>>>>
>>>> #include "drm_crtc_internal.h"
>>>> @@ -289,6 +290,9 @@ int drm_connector_init(struct drm_device
>>>> *dev,
>>>>
>>>> drm_connector_get_cmdline_mode(connector);
>>>>
>>>> + connector->edid_load_pdev = NULL;
>>>> + drm_cache_edid_firmware(connector);
>>>> +
>>>> /* We should add connectors at the end to avoid upsetting the
>>>> connector
>>>> * index too much.
>>>> */
>>>> @@ -473,6 +477,11 @@ void drm_connector_cleanup(struct
>>>> drm_connector *connector)
>>>> connector->tile_group = NULL;
>>>> }
>>>>
>>>> + if (connector->edid_load_pdev) {
>>>> + platform_device_unregister(connector->edid_load_pdev);
>>>> + connector->edid_load_pdev = NULL;
>>>> + }
>>>> +
>>>> list_for_each_entry_safe(mode, t, &connector->probed_modes,
>>>> head)
>>>> drm_mode_remove(connector, mode);
>>>>
>>>> diff --git a/drivers/gpu/drm/drm_edid_load.c
>>>> b/drivers/gpu/drm/drm_edid_load.c
>>>> index 37d8ba3ddb46..5a82be9917ec 100644
>>>> --- a/drivers/gpu/drm/drm_edid_load.c
>>>> +++ b/drivers/gpu/drm/drm_edid_load.c
>>>> @@ -167,6 +167,19 @@ static int edid_size(const u8 *edid, int
>>>> data_size)
>>>> return (edid[0x7e] + 1) * EDID_LENGTH;
>>>> }
>>>>
>>>> +static struct platform_device *edid_pdev(const char
>>>> *connector_name)
>>>> +{
>>>> + struct platform_device *pdev =
>>>> platform_device_register_simple(connector_name, -1, NULL, 0);
>>>> +
>>>> + if (IS_ERR(pdev)) {
>>>> + DRM_ERROR("Failed to register EDID firmware platform device "
>>>> + "for connector \"%s\"\n", connector_name);
>>>> + return ERR_CAST(pdev);
>>>> + }
>>>> +
>>>> + return pdev;
>>>> +}
>>>> +
>>>> static void *edid_load(struct drm_connector *connector, const
>>>> char
>>>> *name,
>>>> const char *connector_name)
>>>> {
>>>> @@ -182,18 +195,17 @@ static void *edid_load(struct drm_connector
>>>> *connector, const char *name,
>>>> fwdata = generic_edid[builtin];
>>>> fwsize = sizeof(generic_edid[builtin]);
>>>> } else {
>>>> - struct platform_device *pdev;
>>>> + struct platform_device *pdev = connector->edid_load_pdev;
>>>> int err;
>>>>
>>>> - pdev = platform_device_register_simple(connector_name, -1,
>>>> NULL,
>>>> 0);
>>>> - if (IS_ERR(pdev)) {
>>>> - DRM_ERROR("Failed to register EDID firmware platform device "
>>>> - "for connector \"%s\"\n", connector_name);
>>>> - return ERR_CAST(pdev);
>>>> + if (WARN_ON(!pdev)) {
>>>> + pdev = edid_pdev(connector_name);
>>>> + if (IS_ERR(pdev))
>>>> + return ERR_CAST(pdev);
>>>> + connector->edid_load_pdev = pdev;
>>>> }
>>>>
>>>> err = request_firmware(&fw, name, &pdev->dev);
>>>> - platform_device_unregister(pdev);
>>>> if (err) {
>>>> DRM_ERROR("Requesting EDID firmware \"%s\" failed
>>>> (err=%d)\n",
>>>> name, err);
>>>> @@ -263,11 +275,9 @@ static void *edid_load(struct drm_connector
>>>> *connector, const char *name,
>>>> return edid;
>>>> }
>>>>
>>>> -struct edid *drm_load_edid_firmware(struct drm_connector
>>>> *connector)
>>>> +static char *edid_name(const char *connector_name)
>>>> {
>>>> - const char *connector_name = connector->name;
>>>> char *edidname, *last, *colon, *fwstr, *edidstr, *fallback =
>>>> NULL;
>>>> - struct edid *edid;
>>>>
>>>> if (edid_firmware[0] == '\0')
>>>> return ERR_PTR(-ENOENT);
>>>> @@ -310,8 +320,57 @@ struct edid *drm_load_edid_firmware(struct
>>>> drm_connector *connector)
>>>> if (*last == '\n')
>>>> *last = '\0';
>>>>
>>>> - edid = edid_load(connector, edidname, connector_name);
>>>> + edidname = kstrdup(edidname, GFP_KERNEL);
>>>> + if (!edidname) {
>>>> + kfree(fwstr);
>>>> + return ERR_PTR(-ENOMEM);
>>>> + }
>>>> +
>>>> kfree(fwstr);
>>>> + return edidname;
>>>> +}
>>>> +
>>>> +void drm_cache_edid_firmware(struct drm_connector *connector)
>>>> +{
>>>> + const char *connector_name = connector->name;
>>>> + const char *edidname = edid_name(connector_name);
>>>> + struct platform_device *pdev;
>>>> + int err;
>>>> +
>>>> + if (IS_ERR(edidname))
>>>> + return;
>>>> +
>>>> + if (match_string(generic_edid_name, GENERIC_EDIDS, edidname) >=
>>>> 0) {
>>>> + kfree(edidname);
>>>> + return;
>>>> + }
>>>> +
>>>> + pdev = edid_pdev(connector_name);
>>>> + if (IS_ERR(pdev)) {
>>>> + kfree(edidname);
>>>> + return;
>>>> + }
>>>> + connector->edid_load_pdev = pdev;
>>>> +
>>>> + err = firmware_request_cache(&pdev->dev, edidname);
>>>> + if (err)
>>>> + DRM_ERROR("Requesting EDID firmware cache \"%s\" failed
>>>> (err=%d)\n",
>>>> + edidname, err);
>>>> +
>>>> + kfree(edidname);
>>>> +}
>>>> +
>>>> +struct edid *drm_load_edid_firmware(struct drm_connector
>>>> *connector)
>>>> +{
>>>> + const char *connector_name = connector->name;
>>>> + const char *edidname = edid_name(connector_name);
>>>> + struct edid *edid;
>>>> +
>>>> + if (IS_ERR(edidname))
>>>> + return ERR_CAST(edidname);
>>>> +
>>>> + edid = edid_load(connector, edidname, connector_name);
>>>> + kfree(edidname);
>>>>
>>>> return edid;
>>>> }
>>>> diff --git a/include/drm/drm_connector.h
>>>> b/include/drm/drm_connector.h
>>>> index 3ac4bf87f257..47c84741517e 100644
>>>> --- a/include/drm/drm_connector.h
>>>> +++ b/include/drm/drm_connector.h
>>>> @@ -1573,6 +1573,18 @@ struct drm_connector {
>>>> */
>>>> struct i2c_adapter *ddc;
>>>>
>>>> + /**
>>>> + * @edid_load_pdev: Platform device for loading EDID via
>>>> firmware.
>>>> + *
>>>> + * The platform device is registered in drm_connector_init() in
>>>> case a
>>>> + * custom EDID firmware is used with `edid_firmware` parameter.
>>>> Otherwise,
>>>> + * it is set to NULL.
>>>> + *
>>>> + * Platform device is unregistered in drm_connector_cleanup()
>>>> if
>>>> it
>>>> + * is not NULL.
>>>> + */
>>>> + struct platform_device *edid_load_pdev;
>>>> +
>>>> /**
>>>> * @null_edid_counter: track sinks that give us all zeros for
>>>> the
>>>> EDID.
>>>> * Needed to workaround some HW bugs where we get all 0s
>>>> diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h
>>>> index b2756753370b..e907c928a35d 100644
>>>> --- a/include/drm/drm_edid.h
>>>> +++ b/include/drm/drm_edid.h
>>>> @@ -378,10 +378,13 @@ int drm_av_sync_delay(struct drm_connector
>>>> *connector,
>>>> const struct drm_display_mode *mode);
>>>>
>>>> #ifdef CONFIG_DRM_LOAD_EDID_FIRMWARE
>>>> +void drm_cache_edid_firmware(struct drm_connector *connector);
>>>> struct edid *drm_load_edid_firmware(struct drm_connector
>>>> *connector);
>>>> int __drm_set_edid_firmware_path(const char *path);
>>>> int __drm_get_edid_firmware_path(char *buf, size_t bufsize);
>>>> #else
>>>> +inline void
>>>> +drm_cache_edid_firmware(struct drm_connector *connector);
>>>> static inline struct edid *
>>>> drm_load_edid_firmware(struct drm_connector *connector)
>>>> {
>>>
>>> --
>>> Jani Nikula, Intel Open Source Graphics Center
>>
>
> --
> Jani Nikula, Intel Open Source Graphics Center
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