From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 015CCC83F1A for ; Fri, 11 Jul 2025 06:08:19 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id A34F510E25D; Fri, 11 Jul 2025 06:08:19 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="V4eKZMWa"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.17]) by gabe.freedesktop.org (Postfix) with ESMTPS id 3744C10E140; Fri, 11 Jul 2025 06:08:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1752214098; x=1783750098; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=cqbUrQ4r9gz47ic5PaDWVtVW/uWNnh1IGO9IT+e0fyM=; b=V4eKZMWadklFnjrtdwia61ayzopplzj4VXZ4qac/T0z1YYJgNDVNV1ix EgfwW9nyhFkykz8aeXwoeazXariyv+kq0i0R3p1RcKTJ9qE4QxSoUYmkW +MBD8jxXRkHUcESLRWX6suCAUT3g0Erqwk4muRuMYXvxlk9SKOkPfk4TQ b1B3Q+sRhoTpA5oQpzQZJTp6YWKbPbRkEH2rvJowsoj13xNVy8LcGG4VD XuF6x9Llz8D6VDL7kbBnDd79ltmWbS9lsyjtqB0drBTGMjisipnfG6g0r ncJmdni3gERV2DFerutdSQwzLTlImt+y2hzko1yMt5CpdiyqUnUpAoXOW A==; X-CSE-ConnectionGUID: Acqn2ZcdQXKshKHqUO1JxA== X-CSE-MsgGUID: cRTa6NC5RXGLf9kLcVGLdQ== X-IronPort-AV: E=McAfee;i="6800,10657,11490"; a="54443352" X-IronPort-AV: E=Sophos;i="6.16,302,1744095600"; d="scan'208";a="54443352" Received: from orviesa001.jf.intel.com ([10.64.159.141]) by fmvoesa111.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Jul 2025 23:08:17 -0700 X-CSE-ConnectionGUID: 85WAU1yrSh6P0fa9AETU9Q== X-CSE-MsgGUID: 1KM2ncc+R6CRGy9AreEiYg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.16,302,1744095600"; d="scan'208";a="193494334" Received: from black.fi.intel.com ([10.237.72.28]) by orviesa001.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Jul 2025 23:08:14 -0700 Date: Fri, 11 Jul 2025 09:08:10 +0300 From: Raag Jadav To: Riana Tauro Cc: Rodrigo Vivi , Christian =?iso-8859-1?Q?K=F6nig?= , Simona Vetter , intel-xe@lists.freedesktop.org, anshuman.gupta@intel.com, lucas.demarchi@intel.com, aravind.iddamsetty@linux.intel.com, umesh.nerlige.ramappa@intel.com, frank.scarbrough@intel.com, sk.anirban@intel.com, =?iso-8859-1?Q?Andr=E9?= Almeida , David Airlie , dri-devel@lists.freedesktop.org Subject: Re: [PATCH v4 1/9] drm: Add a vendor-specific recovery method to device wedged uevent Message-ID: References: <75802ca6-42f9-48e6-bd15-72d2d38f5234@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <75802ca6-42f9-48e6-bd15-72d2d38f5234@intel.com> X-BeenThere: intel-xe@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel Xe graphics driver List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-xe-bounces@lists.freedesktop.org Sender: "Intel-xe" On Fri, Jul 11, 2025 at 10:47:39AM +0530, Riana Tauro wrote: > On 7/11/2025 3:16 AM, Raag Jadav wrote: > > On Thu, Jul 10, 2025 at 03:00:06PM -0400, Rodrigo Vivi wrote: > > > On Thu, Jul 10, 2025 at 01:24:52PM +0300, Raag Jadav wrote: > > > > On Thu, Jul 10, 2025 at 11:37:14AM +0200, Christian König wrote: > > > > > On 10.07.25 11:01, Simona Vetter wrote: > > > > > > On Wed, Jul 09, 2025 at 12:52:05PM -0400, Rodrigo Vivi wrote: > > > > > > > On Wed, Jul 09, 2025 at 05:18:54PM +0300, Raag Jadav wrote: > > > > > > > > On Wed, Jul 09, 2025 at 04:09:20PM +0200, Christian König wrote: > > > > > > > > > On 09.07.25 15:41, Simona Vetter wrote: > > > > > > > > > > On Wed, Jul 09, 2025 at 04:50:13PM +0530, Riana Tauro wrote: > > > > > > > > > > > Certain errors can cause the device to be wedged and may > > > > > > > > > > > require a vendor specific recovery method to restore normal > > > > > > > > > > > operation. > > > > > > > > > > > > > > > > > > > > > > Add a recovery method 'WEDGED=vendor-specific' for such errors. Vendors > > > > > > > > > > > must provide additional recovery documentation if this method > > > > > > > > > > > is used. > > > > > > > > > > > > > > > > > > > > > > v2: fix documentation (Raag) > > > > > > > > > > > > > > > > > > > > > > Cc: André Almeida > > > > > > > > > > > Cc: Christian König > > > > > > > > > > > Cc: David Airlie > > > > > > > > > > > Cc: > > > > > > > > > > > Suggested-by: Raag Jadav > > > > > > > > > > > Signed-off-by: Riana Tauro > > > > > > > > > > > > > > > > > > > > I'm not really understanding what this is useful for, maybe concrete > > > > > > > > > > example in the form of driver code that uses this, and some tool or > > > > > > > > > > documentation steps that should be taken for recovery? > > > > > > > > > > > > > > The case here is when FW underneath identified something badly corrupted on > > > > > > > FW land and decided that only a firmware-flashing could solve the day and > > > > > > > raise interrupt to the driver. At that point we want to wedge, but immediately > > > > > > > hint the admin the recommended action. > > > > > > > > > > > > > > > > > > > > > > > > > The recovery method for this particular case is to flash in a new firmware. > > > > > > > > > > > > > > > > > > > The issues I'm seeing here is that eventually we'll get different > > > > > > > > > > vendor-specific recovery steps, and maybe even on the same device, and > > > > > > > > > > that leads us to an enumeration issue. Since it's just a string and an > > > > > > > > > > enum I think it'd be better to just allocate a new one every time there's > > > > > > > > > > a new strange recovery method instead of this opaque approach. > > > > > > > > > > > > > > > > > > That is exactly the opposite of what we discussed so far. > > > > > > > > > > > > Sorry, I missed that context. > > > > > > > > > > > > > > > The original idea was to add a firmware-flush recovery method which > > > > > > > > > looked a bit wage since it didn't give any information on what to do > > > > > > > > > exactly. > > > > > > > > > > > > > > > > > > That's why I suggested to add a more generic vendor-specific event > > > > > > > > > with refers to the documentation and system log to see what actually > > > > > > > > > needs to be done. > > > > > > > > > > > > > > > > > > Otherwise we would end up with events like firmware-flash, update FW > > > > > > > > > image A, update FW image B, FW version mismatch etc.... > > > > > > > > > > > > Yeah, that's kinda what I expect to happen, and we have enough numbers for > > > > > > this all to not be an issue. > > > > > > > > > > > > > > Agree. Any newly allocated method that is specific to a vendor is going to > > > > > > > > be opaque anyway, since it can't be generic for all drivers. This just helps > > > > > > > > reduce the noise in DRM core. > > > > > > > > > > > > > > > > And yes, there could be different vendor-specific cases for the same driver > > > > > > > > and the driver should be able to provide the means to distinguish between > > > > > > > > them. > > > > > > > > > > > > > > Sim, what's your take on this then? > > > > > > > > > > > > > > Should we get back to the original idea of firmware-flash? > > > > > > > > > > > > Maybe intel-firmware-flash or something, meaning prefix with the vendor? > > > > > > > > > > > > The reason I think it should be specific is because I'm assuming you want > > > > > > to script this. And if you have a big fleet with different vendors, then > > > > > > "vendor-specific" doesn't tell you enough. But if it's something like > > > > > > $vendor-$magic_step then it does become scriptable, and we do have have a > > > > > > place to put some documentation on what you should do instead. > > > > > > > > > > > > If the point of this interface isn't that it's scriptable, then I'm not > > > > > > sure why it needs to be an uevent? > > > > > > > > > > You should probably read up on the previous discussion, cause that is exactly what I asked as well :) > > > > > > > > > > And no, it should *not* be scripted. That would be a bit brave for a firmware update where you should absolutely not power down the system for example. > > > > > > I also don't like the idea or even the thought of scripting something like > > > a firmware-flash. But only to fail with a better pin point to make admin > > > lives easier with a notification. > > > > > > > > > > > > > In my understanding the new value "vendor-specific" basically means it is a known issue with a documented solution, while "unknown" means the driver has no idea how to solve it. > > > > > > Exactly, the hardware and firmware are giving the indication of what should be > > > done. It is not 'unknown'. > > > > > > > > > > > Yes, and since the recovery procedure is defined and known to the consumer, > > > > it can potentially be automated (atleast for non-firmware cases). > > > > > > > > > > I guess if you all want to stick with vendor-specific then I think that's > > > > > > Well, I would honestly prefer a direct firmware-flash, but if that is not > > > usable by other vendors and there's a push back on that, let's go with > > > the vendor-specific then. > > > > I think the procedure for firmware-flash is vendor specific, so the wedged event > > alone is not sufficient either way. The consumer will need more guidance from > > vendor documentation. > > Procedure of firmware-flash is vendor specific, but the term > 'firmware-flash' is still generic. The patch doesn't mention any vendor > specific firmware or procedure. The push back was for the number of macros > that can be added for other operations. A common procedure for the methods is what makes them agnostic and usable for all drivers. Otherwise it's pretty much a chaos for the consumer. > > With vendor-specific method, the driver has the opportunity to cover as many > > cases as it wants without having to create a new method everytime, and face the > > same dilemma of being vendor agnostic. > > > > > > > > ok with me too, but the docs should at least explain how to figure out > > > > > > from the uevent which vendor you're on with a small example. What I'm > > > > > > worried is that if we have this on multiple drivers userspace will > > > > > > otherwise make a complete mess and might want to run the wrong recovery > > > > > > steps. > > > > > > > > The device id along with driver can be identified from uevent (probably > > > > available inside DEVPATH somewhere) to distinguish the vendor. So the consumer > > > > already knows if the device fits the criteria for recovery. > > > > > > > > > > I think ideally, no matter what, we'd have a concrete driver patch which > > > > > > then also comes with the documentation for what exactly you're supposed to > > > > > > do as something you can script. And not just this stand-alone patch here. > > > > > > > > Perhaps the rest of the series didn't make it to dri-devel, which will answer > > > > most of the above. > > > > > > Riana, could you please try to provide a bit more documentation like Sima > > > asked and re-send the entire series to dri-devel? > > Sure will send the entire series to dri-devel. The documentation is present > in the series. > > > > > With the ideas in this thread also documented so that we don't end up repeating > > the same discussion. > It is mentioned in cover letter but i didn't send it to dri-devel. will add > more details Thank you. Raag > > > > > > > > > > > --- > > > > > > > > > > > Documentation/gpu/drm-uapi.rst | 9 +++++---- > > > > > > > > > > > drivers/gpu/drm/drm_drv.c | 2 ++ > > > > > > > > > > > include/drm/drm_device.h | 4 ++++ > > > > > > > > > > > 3 files changed, 11 insertions(+), 4 deletions(-) > > > > > > > > > > > > > > > > > > > > > > diff --git a/Documentation/gpu/drm-uapi.rst b/Documentation/gpu/drm-uapi.rst > > > > > > > > > > > index 263e5a97c080..c33070bdb347 100644 > > > > > > > > > > > --- a/Documentation/gpu/drm-uapi.rst > > > > > > > > > > > +++ b/Documentation/gpu/drm-uapi.rst > > > > > > > > > > > @@ -421,10 +421,10 @@ Recovery > > > > > > > > > > > Current implementation defines three recovery methods, out of which, drivers > > > > > > > > > > > can use any one, multiple or none. Method(s) of choice will be sent in the > > > > > > > > > > > uevent environment as ``WEDGED=[,..,]`` in order of less to > > > > > > > > > > > -more side-effects. If driver is unsure about recovery or method is unknown > > > > > > > > > > > -(like soft/hard system reboot, firmware flashing, physical device replacement > > > > > > > > > > > -or any other procedure which can't be attempted on the fly), ``WEDGED=unknown`` > > > > > > > > > > > -will be sent instead. > > > > > > > > > > > +more side-effects. If recovery method is specific to vendor > > > > > > > > > > > +``WEDGED=vendor-specific`` will be sent and userspace should refer to vendor > > > > > > > > > > > +specific documentation for further recovery steps. If driver is unsure about > > > > > > > > > > > +recovery or method is unknown, ``WEDGED=unknown`` will be sent instead > > > > > > > > > > > Userspace consumers can parse this event and attempt recovery as per the > > > > > > > > > > > following expectations. > > > > > > > > > > > @@ -435,6 +435,7 @@ following expectations. > > > > > > > > > > > none optional telemetry collection > > > > > > > > > > > rebind unbind + bind driver > > > > > > > > > > > bus-reset unbind + bus reset/re-enumeration + bind > > > > > > > > > > > + vendor-specific vendor specific recovery method > > > > > > > > > > > unknown consumer policy > > > > > > > > > > > =============== ======================================== > > > > > > > > > > > diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c > > > > > > > > > > > index cdd591b11488..0ac723a46a91 100644 > > > > > > > > > > > --- a/drivers/gpu/drm/drm_drv.c > > > > > > > > > > > +++ b/drivers/gpu/drm/drm_drv.c > > > > > > > > > > > @@ -532,6 +532,8 @@ static const char *drm_get_wedge_recovery(unsigned int opt) > > > > > > > > > > > return "rebind"; > > > > > > > > > > > case DRM_WEDGE_RECOVERY_BUS_RESET: > > > > > > > > > > > return "bus-reset"; > > > > > > > > > > > + case DRM_WEDGE_RECOVERY_VENDOR: > > > > > > > > > > > + return "vendor-specific"; > > > > > > > > > > > default: > > > > > > > > > > > return NULL; > > > > > > > > > > > } > > > > > > > > > > > diff --git a/include/drm/drm_device.h b/include/drm/drm_device.h > > > > > > > > > > > index 08b3b2467c4c..08a087f149ff 100644 > > > > > > > > > > > --- a/include/drm/drm_device.h > > > > > > > > > > > +++ b/include/drm/drm_device.h > > > > > > > > > > > @@ -26,10 +26,14 @@ struct pci_controller; > > > > > > > > > > > * Recovery methods for wedged device in order of less to more side-effects. > > > > > > > > > > > * To be used with drm_dev_wedged_event() as recovery @method. Callers can > > > > > > > > > > > * use any one, multiple (or'd) or none depending on their needs. > > > > > > > > > > > + * > > > > > > > > > > > + * Refer to "Device Wedging" chapter in Documentation/gpu/drm-uapi.rst for more > > > > > > > > > > > + * details. > > > > > > > > > > > */ > > > > > > > > > > > #define DRM_WEDGE_RECOVERY_NONE BIT(0) /* optional telemetry collection */ > > > > > > > > > > > #define DRM_WEDGE_RECOVERY_REBIND BIT(1) /* unbind + bind driver */ > > > > > > > > > > > #define DRM_WEDGE_RECOVERY_BUS_RESET BIT(2) /* unbind + reset bus device + bind */ > > > > > > > > > > > +#define DRM_WEDGE_RECOVERY_VENDOR BIT(3) /* vendor specific recovery method */ > > > > > > > > > > > /** > > > > > > > > > > > * struct drm_wedge_task_info - information about the guilty task of a wedge dev > > > > > > > > > > > -- > > > > > > > > > > > 2.47.1 > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >