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 B77A5CD5BD5 for ; Wed, 27 May 2026 14:55:19 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 1B21910E851; Wed, 27 May 2026 14:55:19 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="UkU6uQ35"; dkim-atps=neutral Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by gabe.freedesktop.org (Postfix) with ESMTPS id A880C10E851 for ; Wed, 27 May 2026 14:55:18 +0000 (UTC) Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 0A94C6054B; Wed, 27 May 2026 14:55:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 157F41F00A3D; Wed, 27 May 2026 14:55:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1779893717; bh=sY/TVqy3uC7O75twxr1NslKF+o2JmY9Df75dLar6AWc=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=UkU6uQ35ng8UBJZ2ZxsJaHd3FFGLYpNbmVjkbNN1IUww/fqMggQfqqLQjCW+bWWBI unNQFBRXAFbI7NSUnNi95fu0v9OLNFKHRhYKhofp1IvbPgTdlq/w4W0a0vHUadj3hi AhsvtWxQnh1PwVeongwstvX7Mn8K/tyR0CLwi0Ls+n80BbkImNVmL0wuO05ZaIiy2r a3Hal+d+Tm6Q8ag5vMlglseXueafh7943/ihoZw54VjsOZBk8s7KeN7KcMgwPBToIb suHyF2me2ssuBYaooyvyPQu7jaS9Q+UaXKNPY9yZ4TnFdwsXb5/dwxUqsgZumldMj2 /l9FD0epjRMKw== Date: Wed, 27 May 2026 15:55:12 +0100 From: Lee Jones To: Manikandan Muralidharan Cc: maarten.lankhorst@linux.intel.com, mripard@kernel.org, tzimmermann@suse.de, airlied@gmail.com, simona@ffwll.ch, nicolas.ferre@microchip.com, alexandre.belloni@bootlin.com, claudiu.beznea@tuxon.dev, dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 6/8] drm: atmel-hlcdc: add XLCDC clock bypass support for small dividers Message-ID: <20260527145512.GD671544@google.com> References: <20260519090135.1188405-1-manikandan.m@microchip.com> <20260519090135.1188405-7-manikandan.m@microchip.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260519090135.1188405-7-manikandan.m@microchip.com> X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Tue, 19 May 2026, Manikandan Muralidharan wrote: > Define ATMEL_XLCDC_CLKBYP and set the clock bypass bit on XLCDC > hardware when the computed divider is less than 2, avoiding an > invalid divider value. Non-XLCDC hardware retains the existing > minimum divider clamp of 2. > > Signed-off-by: Manikandan Muralidharan > --- > drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c | 7 +++++++ > include/linux/mfd/atmel-hlcdc.h | 1 + Acked-by: Lee Jones > 2 files changed, 8 insertions(+) > > diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c > index 6da428361c19..f837684654ea 100644 > --- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c > +++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c > @@ -87,6 +87,13 @@ static int atmel_hlcdc_crtc_setup_clock(struct atmel_hlcdc_crtc *crtc, > > div = DIV_ROUND_CLOSEST(prate, mode_rate); > if (div < 2) { > + /* XLCDC: bypass divider when div < 2 */ > + if (crtc->dc->desc->is_xlcdc) { > + *cfg |= ATMEL_XLCDC_CLKBYP; > + *mask |= ATMEL_XLCDC_CLKBYP; > + return 0; > + } > + /* Enforce minimum divider for non-XLCDC */ > div = 2; > } else if (ATMEL_HLCDC_CLKDIV(div) & ~ATMEL_HLCDC_CLKDIV_MASK) { > /* The divider ended up too big, try a lower base rate. */ > diff --git a/include/linux/mfd/atmel-hlcdc.h b/include/linux/mfd/atmel-hlcdc.h > index 8e86219293b7..1463c7db0e64 100644 > --- a/include/linux/mfd/atmel-hlcdc.h > +++ b/include/linux/mfd/atmel-hlcdc.h > @@ -44,6 +44,7 @@ > #define ATMEL_XLCDC_HEO_UPDATE BIT(3) > > #define ATMEL_HLCDC_CLKPOL BIT(0) > +#define ATMEL_XLCDC_CLKBYP BIT(1) > #define ATMEL_HLCDC_CLKSEL BIT(2) > #define ATMEL_HLCDC_CLKPWMSEL BIT(3) > #define ATMEL_HLCDC_CGDIS(i) BIT(8 + (i)) > -- > 2.25.1 > -- Lee Jones