From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4E7DBC2BA12 for ; Thu, 2 Apr 2020 07:18:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2AB73208E4 for ; Thu, 2 Apr 2020 07:18:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387579AbgDBHSQ (ORCPT ); Thu, 2 Apr 2020 03:18:16 -0400 Received: from mga04.intel.com ([192.55.52.120]:14313 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728612AbgDBHSQ (ORCPT ); Thu, 2 Apr 2020 03:18:16 -0400 IronPort-SDR: mIWSqvW79cQ6UnJLC8H4+G0SdUJKZU9+v60dazXHFKhVi2b6okQZAdtHAUqcmO9qKxT9D7NvTq Qt+QaQJVEKqw== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Apr 2020 00:18:16 -0700 IronPort-SDR: zyO7eY/PpiDBlijGqIrfpK9HSgBMKM64PHofMZxjeIa//l2/MH+425bKclVjHvWatif5H2HZKX BD9r/3B5EsAg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,334,1580803200"; d="scan'208";a="328726859" Received: from tronach-mobl1.ger.corp.intel.com (HELO kekkonen.fi.intel.com) ([10.252.38.191]) by orsmga001.jf.intel.com with ESMTP; 02 Apr 2020 00:18:09 -0700 Received: by kekkonen.fi.intel.com (Postfix, from userid 1000) id C0C9921F19; Thu, 2 Apr 2020 10:18:01 +0300 (EEST) Date: Thu, 2 Apr 2020 10:18:01 +0300 From: Sakari Ailus To: Hans Verkuil Cc: Petr Mladek , Andy Shevchenko , linux-media@vger.kernel.org, Dave Stevenson , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, laurent.pinchart@ideasonboard.com, mchehab@kernel.org, Sergey Senozhatsky , Steven Rostedt Subject: Re: [PATCH 1/1] lib/vsprintf: Add support for printing V4L2 and DRM fourccs Message-ID: <20200402071801.GA1522@kekkonen.localdomain> References: <20200401140522.966-1-sakari.ailus@linux.intel.com> <080ddddf-717e-61dc-8522-fbdbe52da94a@xs4all.nl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <080ddddf-717e-61dc-8522-fbdbe52da94a@xs4all.nl> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Hans, Thank you for the review. On Wed, Apr 01, 2020 at 04:13:51PM +0200, Hans Verkuil wrote: > On 4/1/20 4:05 PM, Sakari Ailus wrote: > > Add a printk modifier %ppf (for pixel format) for printing V4L2 and DRM > > pixel formats denoted by 4ccs. The 4cc encoding is the same for both so > > the same implementation can be used. > > > > Suggested-by: Mauro Carvalho Chehab > > Signed-off-by: Sakari Ailus > > --- > > Documentation/core-api/printk-formats.rst | 11 +++++++++ > > lib/vsprintf.c | 29 +++++++++++++++++++++++ > > 2 files changed, 40 insertions(+) > > > > diff --git a/Documentation/core-api/printk-formats.rst b/Documentation/core-api/printk-formats.rst > > index 8ebe46b1af39..b6249f513c09 100644 > > --- a/Documentation/core-api/printk-formats.rst > > +++ b/Documentation/core-api/printk-formats.rst > > @@ -545,6 +545,17 @@ For printing netdev_features_t. > > > > Passed by reference. > > > > +V4L2 and DRM fourcc code (pixel format) > > +--------------------------------------- > > + > > +:: > > + > > + %ppf > > + > > +Print a 4cc code used by V4L2 or DRM. > > FourCC appears to be the more-or-less official name (https://en.wikipedia.org/wiki/FourCC) > > I would explain about the -BE suffix for bigendian fourcc variants. Agreed, I'll address these in v2. > > > + > > +Passed by reference. > > + > > Thanks > > ====== > > > > diff --git a/lib/vsprintf.c b/lib/vsprintf.c > > index 7c488a1ce318..b39f0ac317c5 100644 > > --- a/lib/vsprintf.c > > +++ b/lib/vsprintf.c > > @@ -1721,6 +1721,32 @@ char *netdev_bits(char *buf, char *end, const void *addr, > > return special_hex_number(buf, end, num, size); > > } > > > > +static noinline_for_stack > > +char *pixel_format_string(char *buf, char *end, const u32 *fourcc, > > + struct printf_spec spec, const char *fmt) > > +{ > > + char ch[2] = { 0 }; > > This can just be '{ };' As Andy, I also do prefer { 0 }. > > > + unsigned int i; > > + > > + if (check_pointer(&buf, end, fourcc, spec)) > > + return buf; > > + > > + switch (fmt[1]) { > > + case 'f': > > + for (i = 0; i < sizeof(*fourcc); i++) { > > + ch[0] = *fourcc >> (i << 3); > > You need to AND with 0x7f, otherwise a big endian fourcc (bit 31 is set) > will look wrong. Also, each character is standard 7 bit ascii, bit 7 isn't > used except to indicate a BE variant. Good point, will fix for v2. > > > + buf = string(buf, end, ch, spec); > > + } > > + > > + if (*fourcc & BIT(31)) > > + buf = string(buf, end, "-BE", spec); > > + > > + return buf; > > + default: > > + return error_string(buf, end, "(%pp?)", spec); > > + } > > +} > > + > > static noinline_for_stack > > char *address_val(char *buf, char *end, const void *addr, > > struct printf_spec spec, const char *fmt) > > @@ -2131,6 +2157,7 @@ char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode, > > * correctness of the format string and va_list arguments. > > * - 'K' For a kernel pointer that should be hidden from unprivileged users > > * - 'NF' For a netdev_features_t > > + * - 'pf' V4L2 or DRM pixel format. > > I'd say 'FourCC format' instead of 'pixel format'. Will fix. -- Regards, Sakari Ailus