From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfram Sang Subject: Re: [RFC 02/11] i2c: add quirk checks to core Date: Fri, 9 Jan 2015 21:45:22 +0100 Message-ID: <20150109204522.GB1904@katana> References: <1420824103-24169-1-git-send-email-wsa@the-dreams.de> <1420824103-24169-3-git-send-email-wsa@the-dreams.de> <54B02D7F.7040501@cogentembedded.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="wzJLGUyc3ArbnUjN" Return-path: Content-Disposition: inline In-Reply-To: <54B02D7F.7040501-M4DtvfQ/ZS1MRgGoP+s0PdBPR1lH4CV8@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Sergei Shtylyov Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linuxppc-dev-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, linux-mips-6z/3iImG2C8G8FEW9MqTrA@public.gmane.org, Benjamin Herrenschmidt , Ludovic Desroches , Yingjoe Chen , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-i2c@vger.kernel.org --wzJLGUyc3ArbnUjN Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Jan 09, 2015 at 10:35:27PM +0300, Sergei Shtylyov wrote: > Hello. >=20 > On 01/09/2015 08:21 PM, Wolfram Sang wrote: >=20 > >Let the core do the checks if HW quirks prevent a transfer. Saves code > >from drivers and adds consistency. >=20 > >Signed-off-by: Wolfram Sang > >--- > > drivers/i2c/i2c-core.c | 53 ++++++++++++++++++++++++++++++++++++++++++= ++++++++ > > 1 file changed, 53 insertions(+) > > > >diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c > >index 39d25a8cb1ad..7b10a19abf5b 100644 > >--- a/drivers/i2c/i2c-core.c > >+++ b/drivers/i2c/i2c-core.c > >@@ -2063,6 +2063,56 @@ module_exit(i2c_exit); > > * ---------------------------------------------------- > > */ > > > >+/* Check if val is exceeding the quirk IFF quirk is non 0 */ > >+#define i2c_quirk_exceeded(val, quirk) ((quirk) && ((val) > (quirk))) > >+ > >+static int i2c_quirk_error(struct i2c_adapter *adap, struct i2c_msg *ms= g, char *err_msg) > >+{ > >+ dev_err(&adap->dev, "quirk: %s (addr 0x%04x, size %u)\n", err_msg, msg= ->addr, msg->len); > >+ return -EOPNOTSUPP; > >+} >=20 > Always returning the same value doesn't make much sense. Are you trying > to save space on the call sites? Please elaborate. I think it does. If a quirk matches, we report that we don't support this transfer. > [...] > >@@ -2080,6 +2130,9 @@ int __i2c_transfer(struct i2c_adapter *adap, struc= t i2c_msg *msgs, int num) > > unsigned long orig_jiffies; > > int ret, try; > > > >+ if (adap->quirks && i2c_check_for_quirks(adap, msgs, num)) >=20 > So, you only check for non-zero result of this function? Perhaps it ma= kes > sense to return true/false instead? Could be done, but what would be the advantage? A lot of functions return errno or 0. --wzJLGUyc3ArbnUjN Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJUsD3iAAoJEBQN5MwUoCm2IBYP/0XZWZD4A2PX+VdU1SejfyEb wCn0Ys4/8ln9Lo4Xan99vokUdShedP6BxStzkSS+zM7Wmrguh0rfUsfOKB9rwx7+ iBlVUYe9MNV79EjcwL0/iVv5LyRWwjkVZINqiiHEfpYmPlK6JU3PbrspV7AlTB/4 0df1UAN2Vl/OOxWLfUJxY1kB+GDns9EfWXdsWTwCzAO1JGFgry4ALCxA8F96WC56 egQ4KGchqkSSlkrZoP0mfGeU8XQs/15diIoAbrde6dW5uMeedeZfLiA3V9oARZIh yqHDIUjoT76mPDwb8cK+VKsaV0xgaePjwYfbtXstA4oBRHtQbiklfkz/h9uX212v CUdGi3/YuCadhqs6/mF9keK2s6kpBkKOAOo0FOWx1ivETYuIXsmCTDFZW7zB6kHC 2mx3ECHRQq5RadZNGTnuxTKwuNJpmqp1q4FowhRb04/CTHs0LJz4ujMhBlejesmE CTQmn+poeJob2dp4PiLlDwq0GZIz3U23W134sJgIDPk5Fy75Y3K3j9g5hu3HxKEI f0HOgvwlgvsT+V3KjiVJ6oPqgSPA/365WaM8r1+V8bsWiOkITuliTEOaW55lXOWs WrgeMFWmZFKM71KfDtBaYS/4iPb2z8nwfTtQgzvT71mSQoMDD/EILcB6v/nfdfpe c2LBOivFzvqS+hyUTn59 =mCd0 -----END PGP SIGNATURE----- --wzJLGUyc3ArbnUjN--