From mboxrd@z Thu Jan 1 00:00:00 1970 From: "rander.wang" Subject: Re: [alsa-devel] [RFC PATCH 26/40] soundwire: cadence_master: fix divider setting in clock register Date: Fri, 26 Jul 2019 13:56:45 +0800 Message-ID: <552565d2-1734-3c24-3a78-379d08e35110@linux.intel.com> References: <20190725234032.21152-1-pierre-louis.bossart@linux.intel.com> <20190725234032.21152-27-pierre-louis.bossart@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Bard liao , Pierre-Louis Bossart , alsa-devel@alsa-project.org Cc: tiwai@suse.de, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, vkoul@kernel.org, broonie@kernel.org, srinivas.kandagatla@linaro.org, jank@cadence.com, slawomir.blauciak@intel.com, Sanyog Kale List-Id: alsa-devel@alsa-project.org 在 7/26/2019 1:19 PM, Bard liao 写道: > > On 7/26/2019 7:40 AM, Pierre-Louis Bossart wrote: >> From: Rander Wang >> >> The existing code uses an OR operation which would mix the original >> divider setting with the new one, resulting in an invalid >> configuration that can make codecs hang. >> >> Add the mask definition and use cdns_updatel to update divider >> >> Signed-off-by: Rander Wang >> Signed-off-by: Pierre-Louis Bossart >> >> --- >>   drivers/soundwire/cadence_master.c | 12 +++++++----- >>   1 file changed, 7 insertions(+), 5 deletions(-) >> >> diff --git a/drivers/soundwire/cadence_master.c >> b/drivers/soundwire/cadence_master.c >> index 10ebcef2e84e..18c6ac026e85 100644 >> --- a/drivers/soundwire/cadence_master.c >> +++ b/drivers/soundwire/cadence_master.c >> @@ -57,6 +57,7 @@ >>   #define CDNS_MCP_SSP_CTRL1            0x28 >>   #define CDNS_MCP_CLK_CTRL0            0x30 >>   #define CDNS_MCP_CLK_CTRL1            0x38 >> +#define CDNS_MCP_CLK_MCLKD_MASK        GENMASK(7, 0) >>     #define CDNS_MCP_STAT                0x40 >>   @@ -988,9 +989,11 @@ int sdw_cdns_init(struct sdw_cdns *cdns) >>       /* Set clock divider */ >>       divider    = (prop->mclk_freq / prop->max_clk_freq) - 1; >>       val = cdns_readl(cdns, CDNS_MCP_CLK_CTRL0); > > > Do we still need to read cdns_readl(cdns, CDNS_MCP_CLK_CTRL0) > > after this change? > The val is used to print debug message,  and my opinion is to change the log from pr_err("plb: ........") to dev_dbg(bus->dev, "........") to follow the dev_dbg usage in this file. > >> -    val |= divider; >> -    cdns_writel(cdns, CDNS_MCP_CLK_CTRL0, val); >> -    cdns_writel(cdns, CDNS_MCP_CLK_CTRL1, val); >> + >> +    cdns_updatel(cdns, CDNS_MCP_CLK_CTRL0, >> +             CDNS_MCP_CLK_MCLKD_MASK, divider); >> +    cdns_updatel(cdns, CDNS_MCP_CLK_CTRL1, >> +             CDNS_MCP_CLK_MCLKD_MASK, divider); >>         pr_err("plb: mclk %d max_freq %d divider %d register %x\n", >>              prop->mclk_freq, >> @@ -1064,8 +1067,7 @@ int cdns_bus_conf(struct sdw_bus *bus, struct >> sdw_bus_params *params) >>           mcp_clkctrl_off = CDNS_MCP_CLK_CTRL0; >>         mcp_clkctrl = cdns_readl(cdns, mcp_clkctrl_off); > > > Same here. > Also refine the debug log. > >> -    mcp_clkctrl |= divider; >> -    cdns_writel(cdns, mcp_clkctrl_off, mcp_clkctrl); >> +    cdns_updatel(cdns, mcp_clkctrl_off, CDNS_MCP_CLK_MCLKD_MASK, >> divider); >>         pr_err("plb: mclk * 2 %d curr_dr_freq %d divider %d register >> %x\n", >>              prop->mclk_freq * SDW_DOUBLE_RATE_FACTOR,