Ilpo Järvinen f65ba8b988 serial: 8250: fix XOFF/XON sending when DMA is used ... [ Upstream commit f58c252e30cf74f68b0054293adc03b5923b9f0e ] When 8250 UART is using DMA, x_char (XON/XOFF) is never sent to the wire. After this change, x_char is injected correctly. Create uart_xchar_out() helper for sending the x_char out and accounting related to it. It seems that almost every driver does these same steps with x_char. Except for 8250, however, almost all currently lack .serial_out so they cannot immediately take advantage of this new helper. The downside of this patch is that it might reintroduce the problems some devices faced with mixed DMA/non-DMA transfer which caused revert f967fc8f16 (Revert "serial: 8250_dma: don't bother DMA with small transfers"). However, the impact should be limited to cases with XON/XOFF (that didn't work with DMA capable devices to begin with so this problem is not very likely to cause a major issue, if any at all). Fixes: 9ee4b83e51 ("serial: 8250: Add support for dmaengine") Reported-by: Gilles Buloz <gilles.buloz@kontron.com> Tested-by: Gilles Buloz <gilles.buloz@kontron.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220314091432.4288-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>		2022-04-08 14:40:28 +02:00
..
acpi	ACPICA: actypes.h: Expand the ACPI_ACCESS_ definitions	2022-01-27 10:54:18 +01:00
asm-generic
clocksource
crypto
drm
dt-bindings
keys
kunit
kvm
linux	serial: 8250: fix XOFF/XON sending when DMA is used	2022-04-08 14:40:28 +02:00
math-emu
media
memory
misc
net	udp: call udp_encap_enable for v6 sockets when enabling encap	2022-04-08 14:39:54 +02:00
pcmcia
ras
rdma	RDMA/netlink: Add __maybe_unused to static inline in C file	2021-11-26 10:39:21 +01:00
scsi
soc
sound	ALSA: pcm: Fix potential AB/BA lock with buffer_mutex and mmap_lock	2022-04-08 14:39:53 +02:00
target	scsi: target: Fix ordered tag handling	2021-11-26 10:39:11 +01:00
trace	ext4: fix ext4_fc_stats trace point	2022-04-08 14:39:55 +02:00
uapi	rseq: Remove broken uapi field layout on 32-bit little endian	2022-04-08 14:40:03 +02:00
vdso
video
xen	xen/gnttab: fix gnttab_end_foreign_access() without page specified	2022-03-11 12:11:54 +01:00