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Patch "tty: pl011: use "qdf2400_e44" as the earlycon name for QDF2400 E44" has been added to the 4.11-stable tree

PATCH [email protected] 1 participant 1 message May 18, 2017

Subsystems (3)
Stable branch TTY layer and serial drivers Arm primecell UART PL010 and PL011 drivers
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This is a note to let you know that I've just added the patch titled

    tty: pl011: use "qdf2400_e44" as the earlycon name for QDF2400 E44

to the 4.11-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:

     tty-pl011-use-qdf2400_e44-as-the-earlycon-name-for-qdf2400-e44.patch

and it can be found in the queue-4.11 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From 5a0722b898f851b9ef108ea7babc529e4efc773d Mon Sep 17 00:00:00 2001

From: Timur Tabi <[email protected]>
Date: Thu, 13 Apr 2017 08:55:08 -0500
Subject: tty: pl011: use "qdf2400_e44" as the earlycon name for QDF2400 E44

From: Timur Tabi <[email protected]>

commit 5a0722b898f851b9ef108ea7babc529e4efc773d upstream.

Define a new early console name for Qualcomm Datacenter Technologies QDF2400 SOCs affected by erratum 44, instead of piggy-backing on "pl011". Previously, to enable traditional (non-SPCR) earlycon, the documentation said to specify "earlycon=pl011,<address>,qdf2400_e44", but the code was broken and this didn't actually work.

So instead, the method for specifying the E44 work-around with traditional earlycon is "earlycon=qdf2400_e44,<address>". Both methods of earlycon are now enabled with the same function.

Fixes e53e597fd4c4 ("tty: pl011: fix earlycon work-around for QDF2400 erratum 44")
Signed-off-by Timur Tabi <[email protected]>
Tested-by Shanker Donthineni <[email protected]>
Signed-off-by Greg Kroah-Hartman <[email protected]>
---
 drivers/tty/serial/amba-pl011.c |   31 +++++++++++++++++++++++--------
 1 file changed, 23 insertions(+), 8 deletions(-)
drivers/tty/serial/amba-pl011.c +23 -8
@@ -2470,19 +2470,34 @@ static int __init pl011_early_console_se
 	if (!device->port.membase)
 		return -ENODEV;
 
-	/* On QDF2400 SOCs affected by Erratum 44, the "qdf2400_e44" must
-	 * also be specified, e.g. "earlycon=pl011,<address>,qdf2400_e44".
-	 */
-	if (!strcmp(device->options, "qdf2400_e44"))
-		device->con->write = qdf2400_e44_early_write;
-	else
-		device->con->write = pl011_early_write;
+	device->con->write = pl011_early_write;
 
 	return 0;
 }
 OF_EARLYCON_DECLARE(pl011, "arm,pl011", pl011_early_console_setup);
 OF_EARLYCON_DECLARE(pl011, "arm,sbsa-uart", pl011_early_console_setup);
-EARLYCON_DECLARE(qdf2400_e44, pl011_early_console_setup);
+
+/*
+ * On Qualcomm Datacenter Technologies QDF2400 SOCs affected by
+ * Erratum 44, traditional earlycon can be enabled by specifying
+ * "earlycon=qdf2400_e44,<address>".  Any options are ignored.
+ *
+ * Alternatively, you can just specify "earlycon", and the early console
+ * will be enabled with the information from the SPCR table.  In this
+ * case, the SPCR code will detect the need for the E44 work-around,
+ * and set the console name to "qdf2400_e44".
+ */
+static int __init
+qdf2400_e44_early_console_setup(struct earlycon_device *device,
+				const char *opt)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	device->con->write = qdf2400_e44_early_write;
+	return 0;
+}
+EARLYCON_DECLARE(qdf2400_e44, qdf2400_e44_early_console_setup);
 
 #else
 #define AMBA_CONSOLE	NULL

Patches currently in stable-queue which might be from [email protected] are

queue-4.11/tty-pl011-use-qdf2400_e44-as-the-earlycon-name-for-qdf2400-e44.patch