From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laxman Dewangan Subject: Re: [PATCH RFT 3/3] ARM: tegra: dts: seaboard: enable keyboard Date: Sat, 12 Jan 2013 16:04:28 +0530 Message-ID: <50F13C34.3020808@nvidia.com> References: <1357911185-11048-1-git-send-email-ldewangan@nvidia.com> <1357911185-11048-3-git-send-email-ldewangan@nvidia.com> <50F09BC7.90607@wwwdotorg.org> <20130111232438.GN23505@n2100.arm.linux.org.uk> <50F09FCB.70809@wwwdotorg.org> <20130111233615.GO23505@n2100.arm.linux.org.uk> <50F0A2A8.3080401@wwwdotorg.org> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <50F0A2A8.3080401-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Stephen Warren Cc: Russell King - ARM Linux , "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: linux-tegra@vger.kernel.org On Saturday 12 January 2013 05:09 AM, Stephen Warren wrote: > On 01/11/2013 04:36 PM, Russell King - ARM Linux wrote: >> On Fri, Jan 11, 2013 at 04:27:07PM -0700, Stephen Warren wrote: >>> On 01/11/2013 04:24 PM, Russell King - ARM Linux wrote: >>>> On Fri, Jan 11, 2013 at 04:09:59PM -0700, Stephen Warren wrote: >>>>> On 01/11/2013 06:33 AM, Laxman Dewangan wrote: >>>>>> kbc->clk = clk_get(&pdev->dev, NULL); >>>>>> if (IS_ERR(kbc->clk)) { >>>>>> dev_err(&pdev->dev, "failed to get keyboard clock\n"); >>>>>> err = PTR_ERR(kbc->clk); >>>>>> goto err_iounmap; >>>>>> } >>>>> Should that check be if (!kbc-clk) instead? Or does the common clock >>>>> framework require if (IS_ERR_OR_NULL(kbc->clk)); hopefully not since >>>>> IS_ERR_OR_NULL shouldn't be used any more. >>>> /** >>>> * clk_get - lookup and obtain a reference to a clock producer. >>>> * @dev: device for clock "consumer" >>>> * @id: clock consumer ID >>>> * >>>> * Returns a struct clk corresponding to the clock producer, or >>>> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ >>>> * valid IS_ERR() condition containing errno. ... >>>> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ >>>> >>>> Or, put another way: >>>> >>>> If (!IS_ERR(clk)) >>>> The_Clock_Is_Valid(); >>>> Else >>>> The_Clock_Is_Invalid(); >>>> The_Error = PTR_ERR(clk); >>> OK, but that doesn't appear to be what happened in practice. >> It's what I've been saying each time I see an abuse, the problem is >> people don't care to read the documentation provided let alone >> understand the interfaces. >> >> That's precisely why IS_ERR_OR_NULL() is to be removed. One less >> thing for someone to throw a dart at as a selection method to use. >> Or maybe roll a dice. Or whatever way they do seem to choose. >> (Whatever that is, it's not based on any sound engineering practice >> I can make out.) > For the record, I did mention that IS_ERR_OR_NULL() should not be the > solution here. And the point of my email to Laxman was that he should go > figure out the answer to my question, which would entail reading the > documentation/code/... Going through clock driver, the clk_get() should return error pointer or valid pointer, atleast not NULL. Probably our clock driver is returning to NULL and hence issue is becasue whole world, it check for IS_ERR or !IS_ERR() and null clk pointer treated as !IS_ERR(). Stephen, Which is the tree on which Prashant changes are applied. I can debug from that tree.