On 10/9/23 18:46, Paul Barker wrote:
The current SCIF error handling is broken for the RZ/G2L. After a break condition has been triggered, the current code is unable to clear the error and serial port output never resumes.The RZ/G2L datasheet says that most error conditions are cleared by resetting the relevant error bits in the FSR & LSR registers to zero. To clear framing errors, the invalid data also needs to be read out of the receive FIFO. After reviewing datasheets for RZ/G2{H,M,N,E}, R-Car Gen4, R-Car Gen3 and even SH7751 SoCs, it's clear that this is the way to clear errors for all of these SoCs. While we're here, annotate the handle_error() function with a couple of comments as the reads and writes themselves don't immediately make it clear what we're doing. Signed-off-by: Paul Barker <paul.barker...@bp.renesas.com> --- v1->v2: * New patch after discussion with Marek & further investigation. I'm not going to put a `Fixes` tag on this, the error handling has been writing ones to clear errors since at least 2007 so maybe it was originally right for some board. It doesn't seem to apply to any of the current users of the SCIF driver though. drivers/serial/serial_sh.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-)
Tested-by: Marek Vasut <marek.vasut+rene...@mailbox.org> # R-Car H3 Salvator-XS
