mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Finn Thain <fthain@linux-m68k.org>
To: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: linux-m68k@lists.linux-m68k.org, linux-kernel@vger.kernel.org
Subject: [PATCH v3 2/3] m68k: Avoid pointless recursion in debug console rendering
Date: Fri, 28 Mar 2025 09:39:55 +1100	[thread overview]
Message-ID: <a6104f41918bed4fd17f92c45df94ac7a5d30e40.1743115195.git.fthain@linux-m68k.org> (raw)
In-Reply-To: <cover.1743115195.git.fthain@linux-m68k.org>

The recursive call to console_putc to effect a carriage return is
needlessly slow and complicated. Instead, just clear the column counter
directly. Setup %a0 earlier to avoid a repeated comparison.

Signed-off-by: Finn Thain <fthain@linux-m68k.org>
---
 arch/m68k/kernel/head.S | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/arch/m68k/kernel/head.S b/arch/m68k/kernel/head.S
index 9bd8adaa756d..49e079b0d0b5 100644
--- a/arch/m68k/kernel/head.S
+++ b/arch/m68k/kernel/head.S
@@ -3533,19 +3533,16 @@ func_start	console_putc,%a0/%a1/%d0-%d7
 	tstl	%pc@(L(console_font))
 	jeq	L(console_exit)
 
+	lea	%pc@(L(console_globals)),%a0
+
 	/* Output character in d7 on console.
 	 */
 	movel	ARG1,%d7
 	cmpib	#'\n',%d7
-	jbne	1f
+	jne	L(console_not_lf)
 
-	/* A little safe recursion is good for the soul */
-	console_putc	#'\r'
-1:
-	lea	%pc@(L(console_globals)),%a0
+	clrl	%a0@(Lconsole_struct_cur_column)	/* implicit \r */
 
-	cmpib	#10,%d7
-	jne	L(console_not_lf)
 	movel	%a0@(Lconsole_struct_cur_row),%d0
 	movel	%a0@(Lconsole_struct_num_rows),%d1
 	cmpl	%d1,%d0
-- 
2.45.3


  parent reply	other threads:[~2025-03-27 22:44 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-03-27 22:39 [PATCH v3 0/3] m68k: Bug fix and cleanup for framebuffer debug console Finn Thain
2025-03-27 22:39 ` [PATCH v3 1/3] m68k: Fix lost column on " Finn Thain
2025-07-06 10:27   ` Geert Uytterhoeven
2025-03-27 22:39 ` [PATCH v3 3/3] m68k: Remove unused "cursor home" code from " Finn Thain
2025-07-06 10:27   ` Geert Uytterhoeven
2025-03-27 22:39 ` Finn Thain [this message]
2025-07-06 10:27   ` [PATCH v3 2/3] m68k: Avoid pointless recursion in debug console rendering Geert Uytterhoeven
2025-06-11 15:11 ` [PATCH v3 0/3] m68k: Bug fix and cleanup for framebuffer debug console Stan Johnson

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=a6104f41918bed4fd17f92c45df94ac7a5d30e40.1743115195.git.fthain@linux-m68k.org \
    --to=fthain@linux-m68k.org \
    --cc=geert@linux-m68k.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-m68k@lists.linux-m68k.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox

all inboxes | Powered by JetHome®