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