linux-kernel - Re: [PATCH 09/13] soundwire: intel: add CLK_STOP_BUS

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20200818062729.GS2639@vkoul-mobl>
Date:   Tue, 18 Aug 2020 11:57:29 +0530
From:   Vinod Koul <vkoul@...nel.org>
To:     Pierre-Louis Bossart <pierre-louis.bossart@...ux.intel.com>
Cc:     Bard Liao <yung-chuan.liao@...ux.intel.com>,
        alsa-devel@...a-project.org, linux-kernel@...r.kernel.org,
        tiwai@...e.de, broonie@...nel.org, gregkh@...uxfoundation.org,
        jank@...ence.com, srinivas.kandagatla@...aro.org,
        rander.wang@...ux.intel.com, ranjani.sridharan@...ux.intel.com,
        hui.wang@...onical.com, sanyog.r.kale@...el.com,
        slawomir.blauciak@...el.com, mengdong.lin@...el.com,
        bard.liao@...el.com
Subject: Re: [PATCH 09/13] soundwire: intel: add CLK_STOP_BUS_RESET support

On 17-08-20, 09:30, Pierre-Louis Bossart wrote:
> 
> 
> 
> > > +	} else if (clock_stop_quirks & SDW_INTEL_CLK_STOP_BUS_RESET) {
> > > +		ret = sdw_cdns_clock_stop(cdns, true);
> > > +		if (ret < 0) {
> > > +			dev_err(dev, "cannot enable clock stop on suspend\n");
> > > +			return ret;
> > > +		}
> > > +
> > > +		ret = sdw_cdns_enable_interrupt(cdns, false);
> > > +		if (ret < 0) {
> > > +			dev_err(dev, "cannot disable interrupts on suspend\n");
> > > +			return ret;
> > > +		}
> > > +
> > > +		ret = intel_link_power_down(sdw);
> > > +		if (ret) {
> > > +			dev_err(dev, "Link power down failed: %d", ret);
> > > +			return ret;
> > > +		}
> > 
> > no cleanup on all the error cases here?
> 
> See above the 'else if' test, the clock stop on suspend will be followed by
> a bus reset on resume. this is essentially a complete bus restart.

ok

> The only open here is whether we should actually return an error while
> suspending, or just log the error and squelch it. We decided to return the
> status so that the pm_runtime suspend does not proceed: the state remains
> active which is easier to detect than a single line in a dmesg log.

right, returning makes sense and is done correctly above

-- 
~Vinod