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 4E1AEC54EBC for ; Wed, 11 Jan 2023 16:41:35 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id C767510E799; Wed, 11 Jan 2023 16:41:33 +0000 (UTC) Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by gabe.freedesktop.org (Postfix) with ESMTPS id 04A9A10E798; Wed, 11 Jan 2023 16:41:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1673455291; x=1704991291; h=from:to:cc:subject:in-reply-to:references:date: message-id:mime-version; bh=4A4ao5L2r3TfP7WL9syRLryKpdWIe2f8//dXaLYFxYA=; b=QhEfOu0MSEzkNibyDC1JEnN4p6EWn0wvh4cj7vHKPZNF8qW63i8aV27s UFYt0PnaobuNjNDq5l84x2XnDdMw6THnQZG1gIAKX7SCZ3AgWW8PTKJEk vKkwzCM4zPFPD7smGdVWoq69Xn9WE4CnxSRUBiCqALOuK1TTv4adrCezT 7j248jmV+ZX8IkDvukMBm1yzV9nybRKqRZ9vNhYWOmNXe2g3mT7j9F3Nk BK8ZOXoWPCM41yEJhE1DAOQsqXWBVZKi5TzdueQNfWya58IzTk+2WB+ix Vo6ZwXXSIf0fUW5AsPIWGqw4191acRZYVlKmkb+4H6dlwwh3yTZkqhX9W Q==; X-IronPort-AV: E=McAfee;i="6500,9779,10586"; a="325478902" X-IronPort-AV: E=Sophos;i="5.96,317,1665471600"; d="scan'208";a="325478902" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jan 2023 08:40:20 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10586"; a="688008544" X-IronPort-AV: E=Sophos;i="5.96,317,1665471600"; d="scan'208";a="688008544" Received: from mmgriffi-mobl.ger.corp.intel.com (HELO localhost) ([10.252.11.225]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jan 2023 08:40:15 -0800 From: Jani Nikula To: Andi Shyti In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <20230111104447.338136-1-andi.shyti@linux.intel.com> <87a62pi501.fsf@intel.com> Date: Wed, 11 Jan 2023 18:40:13 +0200 Message-ID: <87pmblgh3m.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: [Intel-gfx] [PATCH] drm/i915/pcode: Wait 10 seconds for pcode to settle X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: intel-gfx@lists.freedesktop.org, Rodrigo Vivi , dri-devel@lists.freedesktop.org, Chris Wilson , Chris Wilson Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Wed, 11 Jan 2023, Andi Shyti wrote: > On Wed, Jan 11, 2023 at 03:18:38PM +0200, Jani Nikula wrote: >> On Wed, 11 Jan 2023, Andi Shyti wrote: >> > From: Aravind Iddamsetty >> > >> > During module load not all the punit transaction have completed >> > and we might end up timing out, as shown by the following >> > warning: >> >> Root cause? >> >> > >> > i915 0000:4d:00.0: drm_WARN_ON_ONCE(timeout_base_ms > 3) >> > >> > Wait 10 seconds for the punit to settle and complete any >> > outstanding transactions upon module load. >> > >> > Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/7814 >> > >> >> No blank lines between the tag lines please. > > I don't consider "Closes:" to be a tag even if someone is using > it as such. AFAIK is not mentioned it in any of the kernel docs > (e.g. Documentation/process/maintainer-tip.rst). Basically all of the Something: lines should be bundled together. BR, Jani. > > Not to confuse it with a normal tag, I wanted to put it in > parenthesis or rephrase it. > >> > Signed-off-by: Aravind Iddamsetty >> > Co-developed-by: Chris Wilson >> > Cc: Rodrigo Vivi >> > Signed-off-by: Andi Shyti >> > --- >> > drivers/gpu/drm/i915/intel_pcode.c | 35 ++++++++++++++++++++++++++---- >> > 1 file changed, 31 insertions(+), 4 deletions(-) >> > >> > diff --git a/drivers/gpu/drm/i915/intel_pcode.c b/drivers/gpu/drm/i915/intel_pcode.c >> > index a234d9b4ed14..3db2ba439bb5 100644 >> > --- a/drivers/gpu/drm/i915/intel_pcode.c >> > +++ b/drivers/gpu/drm/i915/intel_pcode.c >> > @@ -204,15 +204,42 @@ int skl_pcode_request(struct intel_uncore *uncore, u32 mbox, u32 request, >> > #undef COND >> > } >> > >> > +static int pcode_init_wait(struct intel_uncore *uncore, int timeout_ms) >> > +{ >> > + if (__intel_wait_for_register_fw(uncore, >> > + GEN6_PCODE_MAILBOX, >> > + GEN6_PCODE_READY, 0, >> > + 500, timeout_ms, >> > + NULL)) >> > + return -EPROBE_DEFER; >> >> This is already done within skl_pcode_request -> skl_pcode_try_request >> -> __snb_pcode_rw path, with waits in skl_pcode_request. > > the idea is to check for PCODE_READY even before checking if > data are sent/received by pcode. And this is only during boot > time. While skl_pcode_request is called in other contexts as > well. > > In other words here I want to start the communication when I > already know that the punit is ready. Otherwise I would hit an > -EAGAIN and fail. > >> Is there anyone who still understands what's being waited for, where, >> for how long, and why in the different code paths? I know I don't, and >> this isn't helping. > > I think it depends on hardware. There are some documents roaming > around with some boot time and reset time calculation. > >> There's also no explanation on the -EPROBE_DEFER return in the commit >> message or comments or anywhere. > > we haven't really failed, right? We just need some time for the > punit to be ready and try to probe again (remember we are here in > module probe). > > Thanks for the review, > Andi > >> Again, root cause? >> >> BR, >> Jani. >> >> >> > + >> > + return skl_pcode_request(uncore, >> > + DG1_PCODE_STATUS, >> > + DG1_UNCORE_GET_INIT_STATUS, >> > + DG1_UNCORE_INIT_STATUS_COMPLETE, >> > + DG1_UNCORE_INIT_STATUS_COMPLETE, timeout_ms); >> > +} >> > + >> > int intel_pcode_init(struct intel_uncore *uncore) >> > { >> > + int err; >> > + >> > if (!IS_DGFX(uncore->i915)) >> > return 0; >> > >> > - return skl_pcode_request(uncore, DG1_PCODE_STATUS, >> > - DG1_UNCORE_GET_INIT_STATUS, >> > - DG1_UNCORE_INIT_STATUS_COMPLETE, >> > - DG1_UNCORE_INIT_STATUS_COMPLETE, 180000); >> > + /* >> > + * Wait 10 seconds so that the punit to settle and complete >> > + * any outstanding transactions upon module load >> > + */ >> > + err = pcode_init_wait(uncore, 10000); >> > + >> > + if (err) { >> > + drm_notice(&uncore->i915->drm, >> > + "Waiting for HW initialisation...\n"); >> > + err = pcode_init_wait(uncore, 180000); >> > + } >> > + >> > + return err; >> > } >> > >> > int snb_pcode_read_p(struct intel_uncore *uncore, u32 mbcmd, u32 p1, u32 p2, u32 *val) >> >> -- >> Jani Nikula, Intel Open Source Graphics Center -- Jani Nikula, Intel Open Source Graphics Center