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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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