|
@@ -0,0 +1,61 @@
|
|
|
+From aaaced6d2d6f796ed77e4725ed7ccbedb189c180 Mon Sep 17 00:00:00 2001
|
|
|
+From: Romain Naour <romain.naour@gmail.com>
|
|
|
+Date: Fri, 15 Jun 2018 17:43:38 +0200
|
|
|
+Subject: [PATCH] Revert: serial: sh-sci: increase RX FIFO trigger defaults for
|
|
|
+ (H)SCIF
|
|
|
+MIME-Version: 1.0
|
|
|
+Content-Type: text/plain; charset=UTF-8
|
|
|
+Content-Transfer-Encoding: 8bit
|
|
|
+
|
|
|
+This reverts commit 18e8cf159177100e69d528293f8cf6875c0b1bca (kernel)
|
|
|
+
|
|
|
+The last Qemu kernel update [1] introduced a regresion in sh4 SCIF
|
|
|
+serial device. Some keyboard presses are very slow to be taken into
|
|
|
+account, perhaps not even taken into account at all. This would
|
|
|
+explain why our test infrastructure doesn’t manage to login as root
|
|
|
+[2][3][4].
|
|
|
+
|
|
|
+git bisect reported a kernel patch from 4.11, increasing RX FIFO
|
|
|
+trigger defaults value for sh-sci (H)SCIF. The kernel patch itself
|
|
|
+looks good but the Qemu emulation is not ready to handle this new
|
|
|
+setting.
|
|
|
+
|
|
|
+From Qemu (2.12.0): target/sh4/README.sh4
|
|
|
+"Configuration of the second serial port (SCIF) is supported. FIFO
|
|
|
+handling infrastructure has been started but is not completed yet."
|
|
|
+
|
|
|
+In order to be able to test sh4 architecture with newer kernel,
|
|
|
+revert to the old behaviour.
|
|
|
+
|
|
|
+[1] https://git.buildroot.net/buildroot/commit/?id=03fb00f2175cdb4565e26fcb9b3da1c1059de1bd
|
|
|
+[2] https://gitlab.com/free-electrons/toolchains-builder/-/jobs/72006425
|
|
|
+[3] https://gitlab.com/free-electrons/toolchains-builder/-/jobs/72006427
|
|
|
+[4] https://gitlab.com/free-electrons/toolchains-builder/-/jobs/72006426
|
|
|
+
|
|
|
+Signed-off-by: Romain Naour <romain.naour@gmail.com>
|
|
|
+Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
|
|
|
+---
|
|
|
+ drivers/tty/serial/sh-sci.c | 7 ++-----
|
|
|
+ 1 file changed, 2 insertions(+), 5 deletions(-)
|
|
|
+
|
|
|
+diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
|
|
|
+index ab757546c6db..138e4dec44fb 100644
|
|
|
+--- a/drivers/tty/serial/sh-sci.c
|
|
|
++++ b/drivers/tty/serial/sh-sci.c
|
|
|
+@@ -2793,11 +2793,8 @@ static int sci_init_single(struct platform_device *dev,
|
|
|
+ sci_port->rx_trigger = 32;
|
|
|
+ break;
|
|
|
+ case PORT_SCIF:
|
|
|
+- if (p->regtype == SCIx_SH7705_SCIF_REGTYPE)
|
|
|
+- /* RX triggering not implemented for this IP */
|
|
|
+- sci_port->rx_trigger = 1;
|
|
|
+- else
|
|
|
+- sci_port->rx_trigger = 8;
|
|
|
++ /* RX triggering not implemented in Qemu emulation */
|
|
|
++ sci_port->rx_trigger = 1;
|
|
|
+ break;
|
|
|
+ default:
|
|
|
+ sci_port->rx_trigger = 1;
|
|
|
+--
|
|
|
+2.14.4
|
|
|
+
|