From patchwork Mon Jan 24 18:44:10 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 535705 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C36A1C4332F for ; Mon, 24 Jan 2022 20:53:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1392620AbiAXUvi (ORCPT ); Mon, 24 Jan 2022 15:51:38 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:47042 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1390922AbiAXUqj (ORCPT ); Mon, 24 Jan 2022 15:46:39 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 7A722B8121C; Mon, 24 Jan 2022 20:46:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 818CEC340E5; Mon, 24 Jan 2022 20:46:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643057195; bh=4LlpM95g7CNgEA0hqrQZzMpteGnWJ4lfkbLqK14oIGw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jBNSDaIFS3ZDeM5I7/pAVBBjtfU5powu4pwmVs900AGWmyioO+rkob53F99mmxWt/ g+dKH3vapBVztYOxF7ndAeEeXJfHZVw2ZKLspdMMLWqhwOVqWJqMwr3W9yvQU5x/5S KVhpIKGH2xNKN2BjqXlWgGjfCcs5KN57PIn5BRpQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Suresh Udipi , Michael Rodin , =?utf-8?q?Niklas_S=C3=B6derlund?= , Hans Verkuil , Mauro Carvalho Chehab Subject: [PATCH 5.15 733/846] media: rcar-csi2: Optimize the selection PHTW register Date: Mon, 24 Jan 2022 19:44:10 +0100 Message-Id: <20220124184126.285314729@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220124184100.867127425@linuxfoundation.org> References: <20220124184100.867127425@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Suresh Udipi commit 549cc89cd09a85aaa16dc07ef3db811d5cf9bcb1 upstream. PHTW register is selected based on default bit rate from Table[1]. for the bit rates less than or equal to 250. Currently first value of default bit rate which is greater than or equal to the caculated mbps is selected. This selection can be further improved by selecting the default bit rate which is nearest to the calculated value. [1] specs r19uh0105ej0200-r-car-3rd-generation.pdf [Table 25.12] Fixes: 769afd212b16 ("media: rcar-csi2: add Renesas R-Car MIPI CSI-2 receiver driver") Signed-off-by: Suresh Udipi Signed-off-by: Michael Rodin Reviewed-by: Niklas Söderlund Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Greg Kroah-Hartman --- drivers/media/platform/rcar-vin/rcar-csi2.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) --- a/drivers/media/platform/rcar-vin/rcar-csi2.c +++ b/drivers/media/platform/rcar-vin/rcar-csi2.c @@ -989,10 +989,17 @@ static int rcsi2_phtw_write_mbps(struct const struct rcsi2_mbps_reg *values, u16 code) { const struct rcsi2_mbps_reg *value; + const struct rcsi2_mbps_reg *prev_value = NULL; - for (value = values; value->mbps; value++) + for (value = values; value->mbps; value++) { if (value->mbps >= mbps) break; + prev_value = value; + } + + if (prev_value && + ((mbps - prev_value->mbps) <= (value->mbps - mbps))) + value = prev_value; if (!value->mbps) { dev_err(priv->dev, "Unsupported PHY speed (%u Mbps)", mbps);