From: Nicolas Pitre <nicolas.pitre@linaro.org>
To: Joe Perches <joe@perches.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Dave Mielke <Dave@mielke.cc>,
Samuel Thibault <samuel.thibault@ens-lyon.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 4/4] vt: coherence validation code for the unicode screen buffer
Date: Tue, 19 Jun 2018 08:14:57 -0400 (EDT) [thread overview]
Message-ID: <nycvar.YSQ.7.76.1806190812550.16670@knanqh.ubzr> (raw)
In-Reply-To: <800831730e3aeaf4da23f7f97cfa80103236c3cb.camel@perches.com>
On Mon, 18 Jun 2018, Joe Perches wrote:
> On Mon, 2018-06-18 at 21:50 -0400, Nicolas Pitre wrote:
> > On Tue, 19 Jun 2018, Andy Shevchenko wrote:
> []
> > > > + /*
> > > > + * Make sure our unicode screen translates into the same glyphs
> > > > + * as the actual screen. This is brutal indeed.
> > > > + */
> > > > + p = (unsigned short *)vc->vc_origin;
> > > > + mask = vc->vc_hi_font_mask | 0xff;
> > > > + for (y = 0; y < vc->vc_rows; y++) {
> > > > + char32_t *line = uniscr->lines[y];
> > > > + for (x = 0; x < vc->vc_cols; x++) {
> > > > + u16 glyph = scr_readw(p++) & mask;
> > > > + char32_t uc = line[x];
> > > > + int tc = conv_uni_to_pc(vc, uc);
> > > > + if (tc == -4)
> > > > + tc = conv_uni_to_pc(vc, 0xfffd);
> > > > + if (tc == -4)
> > > > + tc = conv_uni_to_pc(vc, '?');
> > > > + if (tc != glyph)
> > > > + pr_notice("%s: mismatch at %d,%d: "
> > > > + "glyph=%#x tc=%#x\n", __func__,
> > > > + x, y, glyph, tc);
> > >
> > > Don't split format string in printk(). checkpatch will not warn on longer lines.
> >
> > I didn't do it like that for checkpatch but to keep the code readable.
> > I don't particularly care either ways though.
>
> If one glyph is off, then perhaps others are off too.
> Perhaps this message should be ratelimited.
Remember that this is costly debugging code that is off by default.
No production kernel should have it enabled.
Nicolas
next prev parent reply other threads:[~2018-06-19 12:15 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-17 19:07 [PATCH v2 0/4] have the vt console preserve unicode characters Nicolas Pitre
2018-06-17 19:07 ` [PATCH v2 1/4] vt: preserve unicode values corresponding to screen characters Nicolas Pitre
2018-06-17 22:59 ` valdis.kletnieks
2018-06-17 23:17 ` Nicolas Pitre
2018-06-17 23:23 ` valdis.kletnieks
2018-06-17 19:07 ` [PATCH v2 2/4] vt: introduce unicode mode for /dev/vcs Nicolas Pitre
2018-06-17 19:07 ` [PATCH v2 3/4] vt: unicode fallback for scrollback Nicolas Pitre
2018-06-17 19:07 ` [PATCH v2 4/4] vt: coherence validation code for the unicode screen buffer Nicolas Pitre
2018-06-18 22:01 ` Andy Shevchenko
2018-06-19 1:50 ` Nicolas Pitre
2018-06-19 4:52 ` Joe Perches
2018-06-19 12:14 ` Nicolas Pitre [this message]
2018-06-19 13:09 ` [PATCH v2 0/4] have the vt console preserve unicode characters Adam Borowski
2018-06-19 13:52 ` Dave Mielke
2018-06-19 15:14 ` Adam Borowski
2018-06-19 15:30 ` Dave Mielke
2018-06-19 15:34 ` Nicolas Pitre
2018-06-21 1:43 ` Adam Borowski
2018-06-21 2:21 ` Dave Mielke
2018-06-21 3:03 ` Nicolas Pitre
2018-06-22 1:54 ` Adam Borowski
2018-06-22 6:41 ` Samuel Thibault
2018-06-22 15:59 ` Alan Cox
2018-06-22 16:28 ` Nicolas Pitre
2018-06-22 17:51 ` Alan Cox
2018-06-21 2:59 ` Nicolas Pitre
2018-06-25 0:33 ` Adam Borowski
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