From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: ARC-Seal: i=1; a=rsa-sha256; t=1523554637; cv=none; d=google.com; s=arc-20160816; b=hJfB4+585hjrodyDDRbR1n6j9v3w/LKZS/4yyblgtGkvlo5P2ERcPwBD1+tu89UEY7 UGXquWdDmv4BijIQ/Wh1UhLfPmj2epmGypuitqeuWkY0kRf8pcbEfDLc1gKvxA+GiN0d zC5k4qOk8a+sE/2nG80sx72Yh8QgInQbHKoJqvT/SQj/+cxiTIrPgo502hmKajjoMzF3 eDHHOBbJmXlNpxdyDzk4TXjXB1jfUMjKf0M86P3eMxjhqaMtOKya4tv+mu0G8+a1pB5v VuZW2NVUECyJtm2oQ0poRvt+HgIbY5Rxll+TQOmNRI0GzaI4jlpLjSWECXNsnM3elTii SDvg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=user-agent:in-reply-to:content-transfer-encoding :content-disposition:mime-version:references:message-id:subject:cc :to:from:date:sender:dkim-signature:arc-authentication-results; bh=RUSXcbBkt1fxkghag2nr5gB4UuXXw0/dkFAKGZ7lYIc=; b=qrqaBN/HcMFisQ+a3ejQMOfp0xE1Z7xwrvxQdXjWwKBPlNprVFQzdYg7WtGzwN9tHo 54/kDFAW0F0USpkWR6UNrb9wmqyAixueuzQ7i6pdKYKv0kDyBO/aJ0AS7LqOb7+sgWSo oXiqc62D+dhnZq2hvVmAWdzxyD74ZkoS+AKqsi4A0v3jPAJ5xH9nXT6JM+wKxhYW896F myCMkcW0i5IEiimEm/tNDjNkAm9i2Z2mkSRe4QvEx3hb7xcjmM6bkrMoLRuHqqQUTzqD 7YCcVj2aaIgCoB/Bxq0uAFnMYlUJ19hXu4H9umQc/kbmSHXOlsuCFbczsPull7ERsCDG BIhQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=MxfmZgvf; spf=pass (google.com: domain of groeck7@gmail.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=groeck7@gmail.com Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=MxfmZgvf; spf=pass (google.com: domain of groeck7@gmail.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=groeck7@gmail.com X-Google-Smtp-Source: AIpwx4/11sS6SoqNZpw9C60HKIjPoqTnVsScmLe46MCGuOQzDzWZV14lyNunDFh69+HNAY7QaTfPnw== Sender: Guenter Roeck Date: Thu, 12 Apr 2018 10:37:14 -0700 From: Guenter Roeck To: Jae Hyun Yoo Cc: Alan Cox , Andrew Jeffery , Andrew Lunn , Andy Shevchenko , Arnd Bergmann , Benjamin Herrenschmidt , Fengguang Wu , Greg KH , Haiyue Wang , James Feist , Jason M Biils , Jean Delvare , Joel Stanley , Julia Cartwright , Miguel Ojeda , Milton Miller II , Pavel Machek , Randy Dunlap , Stef van Os , Sumeet R Pawnikar , Vernon Mauery , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, devicetree@vger.kernel.org, linux-hwmon@vger.kernel.org, linux-arm-kernel@lists.infradead.org, openbmc@lists.ozlabs.org Subject: Re: [PATCH v3 09/10] drivers/hwmon: Add PECI hwmon client drivers Message-ID: <20180412173714.GA13496@roeck-us.net> References: <20180410183212.16787-1-jae.hyun.yoo@linux.intel.com> <20180410183212.16787-10-jae.hyun.yoo@linux.intel.com> <20180410222800.GA8484@roeck-us.net> <637d7812-e567-0bc2-4f08-fbdca0ee85d8@linux.intel.com> <292be2d9-e572-2e06-9899-f6c2c53fdefc@roeck-us.net> <7b378954-1ce8-a2d2-5d09-8b6b36c048be@linux.intel.com> <13d4c632-a20e-3c40-066a-1e9df02a0595@roeck-us.net> <89c8c847-87e7-a849-e05d-d32b787e9305@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <89c8c847-87e7-a849-e05d-d32b787e9305@linux.intel.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1597385144123845129?= X-GMAIL-MSGID: =?utf-8?q?1597562827253899656?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Thu, Apr 12, 2018 at 10:09:51AM -0700, Jae Hyun Yoo wrote: [ ... ] > >>>>>>+static int find_core_index(struct peci_cputemp *priv, int channel) > >>>>>>+{ > >>>>>>+    int core_channel = channel - DEFAULT_CHANNEL_NUMS; > >>>>>>+    int idx, found = 0; > >>>>>>+ > >>>>>>+    for (idx = 0; idx < priv->gen_info->core_max; idx++) { > >>>>>>+        if (priv->core_mask & BIT(idx)) { > >>>>>>+            if (core_channel == found) > >>>>>>+                break; > >>>>>>+ > >>>>>>+            found++; > >>>>>>+        } > >>>>>>+    } > >>>>>>+ > >>>>>>+    return idx; > >>>>> > >>>>>What if nothing is found ? > >>>>> > >>>> > >>>>Core temperature group will be registered only when it detects at > >>>>least one core checked by check_resolved_cores(), so > >>>>find_core_index() can be called only when priv->core_mask has a > >>>>non-zero value. The 'nothing is found' case will not happen. > >>>> > >>>That doesn't guarantee a match. If what you are saying is correct > >>>there should always be > >>>a well defined match of channel -> idx, and the search should be > >>>unnecessary. > >>> > >> > >>There could be some disabled cores in the resolved core mask bit > >>sequence also it should remove indexing gap in channel numbering so it > >>is the reason why this search function is needed. Well defined match of > >>channel -> idx would not be always satisfied. > >> > >Are you saying that each call to the function, with the same parameters, > >can return a different result ? > > > > No, the result will be consistent. After reading the priv->core_mask once in > check_resolved_cores(), the value will not be changed. I'm saying about this > case, for example if core number 2 is unresolved in total 4 cores, then the > idx order will be '0, 1, 3' but channel order will be '5, 6, 7' without > making any indexing gap. > And you yet you claim that this is not well defined ? Or are you concerned about the amount of memory consumed by providing an array for the mapping ? Note that an indexing gap is acceptable and, in many cases, preferred. [ ... ] > >>>>>>+ > >>>>>>+    dev_dbg(dev, "%s: sensor '%s'\n", dev_name(hwmon_dev), > >>>>>>priv->name); > >>>>>>+ > >>> > >>>Why does this message display the device name twice ? > >>> > >> > >>For an example, dev_name(hwmon_dev) shows 'hwmon5' and priv->name shows > >>'peci-cputemp0'. > >> > >And dev_dbg() shows another device name. So you'll have something like > > > >peci-cputemp0: hwmon5: sensor 'peci-cputemp0' > > > > Practically it shows like > > peci-cputemp 0-30:00: hwmon10: sensor 'peci_cputemp.cpu0' > > where 0-30:00 is assigned by peci core. > And what message would you see for cpu1 ?