| 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 |
| |
