From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.16]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3A63F3803CD for ; Tue, 13 Jan 2026 08:55:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768294551; cv=none; b=StiDjWNhyOxp0an9Zbo3tXD2LTfI7i45PGSgmaHjnVDTAcK8LiECftkd3HFoJo4c7sQgtNdl2C+MtlQc6iM8aTPATsz+u7GRjKk2tK79nzabIZ+i+fyCkx9KSZ8jSiMikyFeQpiEhR8DhzWBmJl1yp3UToS1Vt8Bxs72bf+AeOg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768294551; c=relaxed/simple; bh=FKsZ7/c2YYqd7B+iTZGZ/2CJD+QcEC6jH1mrDC+vkEI=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=ijNJx8KBbqgWm4AGF+H1COSQTi8CXBWuxkFEsApOETZlEL9KZzD8mxDIwGClgt9kpjIxsxRDg0XECBRT+Sm4hbM9ib9eNgRn0mAKTG2ideu0+d03p+cR0WrMMR+CPwv1DlIAeAbPKkx5MCE4w58ohmxrmS8ZzEYcBcWobYKBS0c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=d1rVjRMk; arc=none smtp.client-ip=198.175.65.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="d1rVjRMk" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1768294549; x=1799830549; h=from:to:cc:subject:in-reply-to:references:date: message-id:mime-version; bh=FKsZ7/c2YYqd7B+iTZGZ/2CJD+QcEC6jH1mrDC+vkEI=; b=d1rVjRMk0eT0J1UfYLhQoAmoOaSiL4GPPkL8I/o+WGMvcXngeadzledX l7ee6IisWvVcy5so9ikRhnlwPApeZjwgvs9wGlrhByIIBacHRNyAJiRHk l0D9pPmSNeIxAwlSBFxFvDMe8ttAywiPqprBhoyIpHk/dwkY0HUvnxR28 rQNesXjmZoIu2G9FXtkB/Hmjm5l3db+C6q82yElwEh2QPHYtVY7uiCos4 vTqo86MfdSaf4Edq8jI7iz/tNaUPMqFqp2aUPXo5MLeZ3ANp2ax5ZypLe X+lv4TQFhDe64fCWTLMmwHdiKB07HwHi8ueCp9htX5mxg9lHg7Ua6d1dW g==; X-CSE-ConnectionGUID: M0jSFVxuSpi1rXEmRx+xBA== X-CSE-MsgGUID: /Jxo2+kYSU+tiPdJIPATtg== X-IronPort-AV: E=McAfee;i="6800,10657,11669"; a="69734691" X-IronPort-AV: E=Sophos;i="6.21,222,1763452800"; d="scan'208";a="69734691" Received: from orviesa008.jf.intel.com ([10.64.159.148]) by orvoesa108.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Jan 2026 00:55:49 -0800 X-CSE-ConnectionGUID: gZemEsFaTnumJhnmSSZSTw== X-CSE-MsgGUID: LN8Z9Q5OQaWqCYdJiPfE5w== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,222,1763452800"; d="scan'208";a="204413183" Received: from jkrzyszt-mobl2.ger.corp.intel.com (HELO localhost) ([10.245.246.36]) by orviesa008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Jan 2026 00:55:46 -0800 From: Jani Nikula To: TrainedPro , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann Cc: David Airlie , Daniel Vetter , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, TrainedPro Subject: Re: [PATCH] drm/display: Bump LSPCON mode switch timeout to 1000ms In-Reply-To: <20260111180320.4047086-1-hassaananwar12345@gmail.com> Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs Bertel Jungin Aukio 5, 02600 Espoo, Finland References: <20260111180320.4047086-1-hassaananwar12345@gmail.com> Date: Tue, 13 Jan 2026 10:55:43 +0200 Message-ID: <4a61f6ec7ecb9e0c25ba657098377fb2d8bf6191@intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain On Sun, 11 Jan 2026, TrainedPro wrote: > The Parade PS175 LSPCON chip often requires up to 800ms to settle after a mode change, particularly during resume. > > Although the Intel driver (intel_lspcon.c) is aware of this 800ms requirement, it calls the shared helper `drm_lspcon_set_mode()`, which currently hardcodes a 200ms timeout. This specific implementation forces a 200ms limit, effectively overriding the driver's knowledge and causing the mode change to time out prematurely, which results in a black screen (never waking up). > > This patch increases the hardcoded timeout in the helper from 200ms to 1000ms. Since the function polls for the status bit, this change does not penalize faster chips but ensures correct operation for slower ones like the PS175. > > Signed-off-by: TrainedPro Is there an existing gitlab issue with dmesg logs about the issue? See [1] for how to report one. BR, Jani. [1] https://drm.pages.freedesktop.org/intel-docs/how-to-file-i915-bugs.html > --- > drivers/gpu/drm/display/drm_dp_dual_mode_helper.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c b/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c > index 719da3610310f..fda3cb4966adf 100644 > --- a/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c > +++ b/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c > @@ -495,7 +495,7 @@ int drm_lspcon_set_mode(const struct drm_device *dev, struct i2c_adapter *adapte > { > u8 data = 0; > int ret; > - int time_out = 200; > + int time_out = 1000; > enum drm_lspcon_mode current_mode; > > if (mode == DRM_LSPCON_MODE_PCON) -- Jani Nikula, Intel