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patch "tty: pl011: use "qdf2400_e44" as the earlycon name for QDF2400 E44" added to tty-next

PATCH [email protected] 1 participant 1 message May 3, 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 my tty git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git
in the tty-next branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will also be merged in the next major kernel release during the merge window.

If you have any questions about this process, please let me know.

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

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]>
Cc stable <[email protected]> # 4.11
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
index 37257badcb97..8a857bb34fbb 100644
@@ -2475,19 +2475,34 @@ static int __init pl011_early_console_setup(struct earlycon_device *device,
 	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
Signature · 1 line
2.12.2