From patchwork Fri Jul 21 16:53:27 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lucas Stach X-Patchwork-Id: 13322369 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 F039DEB64DC for ; Fri, 21 Jul 2023 16:53:37 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 8816610E6DE; Fri, 21 Jul 2023 16:53:33 +0000 (UTC) Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by gabe.freedesktop.org (Postfix) with ESMTPS id 0F06C10E6DC for ; Fri, 21 Jul 2023 16:53:30 +0000 (UTC) Received: from dude02.red.stw.pengutronix.de ([2a0a:edc0:0:1101:1d::28]) by metis.ext.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1qMtNh-0006s5-7m; Fri, 21 Jul 2023 18:53:29 +0200 From: Lucas Stach To: dri-devel@lists.freedesktop.org Subject: [PATCH v2 1/2] drm/bridge: tc358767: increase PLL lock time delay Date: Fri, 21 Jul 2023 18:53:27 +0200 Message-Id: <20230721165328.3968759-1-l.stach@pengutronix.de> X-Mailer: git-send-email 2.39.2 MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2a0a:edc0:0:1101:1d::28 X-SA-Exim-Mail-From: l.stach@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: dri-devel@lists.freedesktop.org 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: , Cc: Marek Vasut Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: David Jander The PLL often fails to lock with this delay. The new value was determined by trial and error increasing the delay bit by bit until the error did not occurr anymore even after several tries. Then double that value was taken as the minimum delay to be safe. Signed-off-by: David Jander Signed-off-by: Lucas Stach Reviewed-by: Marek Vasut Tested-by: Marek Vasut # TC9595 Reviewed-by: Marek Vasut --- v2: correct comment --- drivers/gpu/drm/bridge/tc358767.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c index 65dc842e31f0..29721e26de5d 100644 --- a/drivers/gpu/drm/bridge/tc358767.c +++ b/drivers/gpu/drm/bridge/tc358767.c @@ -500,8 +500,8 @@ static int tc_pllupdate(struct tc_data *tc, unsigned int pllctrl) if (ret) return ret; - /* Wait for PLL to lock: up to 2.09 ms, depending on refclk */ - usleep_range(3000, 6000); + /* Wait for PLL to lock: up to 7.5 ms, depending on refclk */ + usleep_range(15000, 20000); return 0; }