> From: Ulrich Hecht, Sent: Thursday, February 15, 2018 9:02 PM
> When the TTY buffers fill up to the configured maximum, a system lockup
> [ 598.820128] INFO: rcu_preempt detected stalls on CPUs/tasks:
> [ 598.825796] 0-...!: (1 GPs behind) idle=5a6/2/0 softirq=1974/1974 fqs=1
> [ 598.832577] (detected by 3, t=62517 jiffies, g=296, c=295, q=126)
> [ 598.838755] Task dump for CPU 0:
> [ 598.841977] swapper/0 R running task 0 0 0
> [ 598.849023] Call trace:
> [ 598.851476] __switch_to+0x98/0xb0
> [ 598.854870] (null)
> This can be prevented by doing a dummy read of the RX data register.
> This issue affects both HSCIF and SCIF ports. Reported for R-Car H3 ES2.0;
> reproduced and fixed on H3 ES1.1. Probably affects other R-Car platforms
> as well.
> Reported-by: Yoshihiro Shimoda <yoshihiro.shimoda...@renesas.com>
> Signed-off-by: Ulrich Hecht <ulrich.hecht+rene...@gmail.com>
Thank you for the patch. Our team tested this patch and the issue disappeared.
Tested-by: Nguyen Viet Dung <dung.nguyen...@renesas.com>