From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754745AbcCWKh7 (ORCPT ); Wed, 23 Mar 2016 06:37:59 -0400 Received: from foss.arm.com ([217.140.101.70]:45475 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752393AbcCWKhw (ORCPT ); Wed, 23 Mar 2016 06:37:52 -0400 Subject: Re: [PATCH 03/14] coresight: tmc: re-implementing tmc_read_prepare/unprepare() functions To: Mathieu Poirier References: <1458678202-3447-1-git-send-email-mathieu.poirier@linaro.org> <1458678202-3447-4-git-send-email-mathieu.poirier@linaro.org> Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org From: "Suzuki K. Poulose" Message-ID: <56F271FE.8060904@arm.com> Date: Wed, 23 Mar 2016 10:37:50 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 In-Reply-To: <1458678202-3447-4-git-send-email-mathieu.poirier@linaro.org> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 22/03/16 20:23, Mathieu Poirier wrote: > In their current implementation the tmc_read_prepare/unprepare() > are a lump of if/else that is difficult to read. This patch is > alleviating that by using a switch statement. The latter also > allows for a better control on the error path. > > Signed-off-by: Mathieu Poirier > --- > drivers/hwtracing/coresight/coresight-tmc.c | 56 ++++++++++++++++++----------- > 1 file changed, 36 insertions(+), 20 deletions(-) > > diff --git a/drivers/hwtracing/coresight/coresight-tmc.c b/drivers/hwtracing/coresight/coresight-tmc.c > index f4ba837a0810..208d47dd3083 100644 > --- a/drivers/hwtracing/coresight/coresight-tmc.c > +++ b/drivers/hwtracing/coresight/coresight-tmc.c > @@ -430,7 +430,7 @@ static const struct coresight_ops tmc_etf_cs_ops = { > > - if (drvdata->config_type == TMC_CONFIG_TYPE_ETB) { > + switch (drvdata->config_type) { > + case TMC_CONFIG_TYPE_ETB: > tmc_etb_disable_hw(drvdata); > - } else if (drvdata->config_type == TMC_CONFIG_TYPE_ETR) { > - tmc_etr_disable_hw(drvdata); > - } else { > + break; > + case TMC_CONFIG_TYPE_ETF: > + /* There is no point in reading a TMC in HW FIFO mode */ > mode = readl_relaxed(drvdata->base + TMC_MODE); > - if (mode == TMC_MODE_CIRCULAR_BUFFER) { > - tmc_etb_disable_hw(drvdata); > - } else { > - ret = -ENODEV; > + if (mode != TMC_MODE_CIRCULAR_BUFFER) { > + ret = -EINVAL; > goto err; > } > + > + tmc_etb_disable_hw(drvdata); > + break; > + case TMC_CONFIG_TYPE_ETR: > + tmc_etr_disable_hw(drvdata); > + break; > + default: > + ret = -EINVAL; > + goto err; > } We seem to be doing this switch at different places in the code just for enable_hw/disable_hw. e.g, tmc_enable, tmc_disable Could we make this a bit more cleaner by introducing something like this ? struct tmc_hw_ops { int (*enable_hw)(struct tmc_drvdata *drvdata, enum tmc_mode mode); int (*disable_hw)(struct tmc_drvdata *drvdata, enum tmc_mode mode); }; struct tmc_hw_ops tmc_etf_ops = { tmc_etf_enable_hw, tmc_etf_disable_hw, }; similiarly for etb and etr and then add struct tmc_hw_ops *hw_ops to tmc_drvdata, initialised at probe time (while reading the config_type). Suzuki