public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Thorsten Blum <thorsten.blum@linux.dev>
To: Thomas Gleixner <tglx@kernel.org>, Ingo Molnar <mingo@redhat.com>,
	Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>
Cc: Thorsten Blum <thorsten.blum@linux.dev>, linux-kernel@vger.kernel.org
Subject: [PATCH 2/2] x86/boot: use BASE_BAUD and DEFAULT_SERIAL_PORT
Date: Sat, 11 Apr 2026 17:34:51 +0200	[thread overview]
Message-ID: <20260411153449.69384-6-thorsten.blum@linux.dev> (raw)
In-Reply-To: <20260411153449.69384-4-thorsten.blum@linux.dev>

Replace the hard-coded divisor and ttyS0 port with the existing
BASE_BAUD and DEFAULT_SERIAL_PORT macros.

In parse_earlyprintk(), assign 'port' directly and drop the redundant
index variable as well as the 'bases' array to simplify the code.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
---
 arch/x86/boot/early_serial_console.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/arch/x86/boot/early_serial_console.c b/arch/x86/boot/early_serial_console.c
index fe0c8c1022f4..420f50f3bd1e 100644
--- a/arch/x86/boot/early_serial_console.c
+++ b/arch/x86/boot/early_serial_console.c
@@ -34,7 +34,7 @@ static void early_serial_init(int port, int baud)
 	outb(0, port + FCR);	/* no fifo */
 	outb(0x3, port + MCR);	/* DTR + RTS */
 
-	divisor	= 115200 / baud;
+	divisor	= BASE_BAUD / baud;
 	c = inb(port + LCR);
 	outb(c | DLAB, port + LCR);
 	outb(divisor & 0xff, port + DLL);
@@ -75,16 +75,13 @@ static void parse_earlyprintk(void)
 			else
 				pos = e - arg;
 		} else if (!strncmp(arg + pos, "ttyS", 4)) {
-			static const int bases[] = { 0x3f8, 0x2f8 };
-			int idx = 0;
-
 			/* += strlen("ttyS"); */
 			pos += 4;
 
 			if (arg[pos++] == '1')
-				idx = 1;
-
-			port = bases[idx];
+				port = 0x2f8; /* ttyS1 */
+			else
+				port = DEFAULT_SERIAL_PORT;
 		}
 
 		if (arg[pos] == ',')

      reply	other threads:[~2026-04-11 15:36 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-04-11 15:34 [PATCH 1/2] x86/boot: validate earlyprintk= baud rate Thorsten Blum
2026-04-11 15:34 ` Thorsten Blum [this message]

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=20260411153449.69384-6-thorsten.blum@linux.dev \
    --to=thorsten.blum@linux.dev \
    --cc=bp@alien8.de \
    --cc=dave.hansen@linux.intel.com \
    --cc=hpa@zytor.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=tglx@kernel.org \
    --cc=x86@kernel.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