From mboxrd@z Thu Jan 1 00:00:00 1970 From: Archit Taneja Subject: [PATCH] clk: qcom: fix RCG M/N counter configuration Date: Wed, 4 Mar 2015 15:19:35 +0530 Message-ID: <1425462575-11486-1-git-send-email-architt@codeaurora.org> Return-path: Received: from smtp.codeaurora.org ([198.145.29.96]:53963 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759081AbbCDJtn (ORCPT ); Wed, 4 Mar 2015 04:49:43 -0500 Sender: linux-arm-msm-owner@vger.kernel.org List-Id: linux-arm-msm@vger.kernel.org To: sboyd@codeaurora.org Cc: mturquette@linaro.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, Archit Taneja Currently, a RCG's M/N counter (used for fraction division) is set to either 'bypass' (counter disabled) or 'dual edge' (counter enabled) based on whether the corresponding rcg struct has a mnd field specified and a non-zero N. In the case where M and N are the same value, the M/N counter is still enabled by code even though no division takes place. Leaving the RCG in such a state can result in improper behavior. This was observed with the DSI pixel clock RCG when M and N were both set to 1. Add an additional check (M != N) to enable the M/N counter only when it's needed for fraction division. Signed-off-by: Archit Taneja --- drivers/clk/qcom/clk-rcg2.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/clk/qcom/clk-rcg2.c b/drivers/clk/qcom/clk-rcg2.c index 08b8b37..4fe9c01 100644 --- a/drivers/clk/qcom/clk-rcg2.c +++ b/drivers/clk/qcom/clk-rcg2.c @@ -242,7 +242,7 @@ static int clk_rcg2_configure(struct clk_rcg2 *rcg, const struct freq_tbl *f) mask |= CFG_SRC_SEL_MASK | CFG_MODE_MASK; cfg = f->pre_div << CFG_SRC_DIV_SHIFT; cfg |= rcg->parent_map[f->src] << CFG_SRC_SEL_SHIFT; - if (rcg->mnd_width && f->n) + if (rcg->mnd_width && f->n && (f->m != f->n)) cfg |= CFG_MODE_DUAL_EDGE; ret = regmap_update_bits(rcg->clkr.regmap, rcg->cmd_rcgr + CFG_REG, mask, cfg); -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, hosted by The Linux Foundation