| 12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061 |
- 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
|
