From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jean Delvare Subject: Re: [PATCH] i2c: i2c-gpio: fix issue when DT node greater than 1 Date: Wed, 19 Sep 2012 17:54:33 +0200 Message-ID: <20120919175433.3841a954@endymion.delvare> References: <1347958949-5598-1-git-send-email-voice.shen@atmel.com> <50588A8F.30203@wwwdotorg.org> <50591C9C.2080809@atmel.com> <5059E484.6090708@wwwdotorg.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <5059E484.6090708-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Stephen Warren Cc: Bo Shen , devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, nicolas.ferre-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org, linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, plagnioj-sclMFOaUSTBWk0Htik3J/w@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, hskinnemoen-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org List-Id: linux-i2c@vger.kernel.org On Wed, 19 Sep 2012 09:28:04 -0600, Stephen Warren wrote: > On 09/18/2012 07:15 PM, Bo Shen wrote: > > I add the debug info, and it give the following error without this patch. > > > > --<8---------------------------------- > > adap->name = i2c-gpio-1 > > i2c-gpio i2c.2: using pins 30 (SDA) and 31 (SCL) > > adap->name = i2c-gpio-1 > > i2c-gpio: probe of i2c.3 failed with error -16 > > -->8---------------------------------- > > > > With this patch, it successfully registered. > > --<8---------------------------------- > > adap->name = i2c-gpio0 > > i2c-gpio i2c.2: using pins 30 (SDA) and 31 (SCL) > > adap->name = i2c-gpio1 > > i2c-gpio i2c.3: using pins 90 (SDA) and 91 (SCL) > > -->8---------------------------------- > > Yes, that explains why the registration fails, but not why this patch is > the correct solution to the problem. > > The problematic code appears to be: > > snprintf(adap->name, sizeof(adap->name), "i2c-gpio%d", pdev->id); > > Instead, I think that should be something more like: > > adap->name = dev_name(&pdev->dev); strlcpy(adap->name, dev_name(&pdev->dev), sizeof(adap->name)) if anything, as adap->name is a buffer, not a pointer. > or perhaps: > > if (pdev->dev.of_node) > /* named will be based on DT node name */ > adap->name = dev_name(&pdev->dev); > else > snprintf(adap->name, sizeof(adap->name), "i2c-gpio%d", pdev->id); > > ? -- Jean Delvare