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Filename Latest commit message Latest commit date
Maciej W. Rozycki 47e4c42faa serial: sifive: Report actual baud base rather than fixed 115200
[ Upstream commit 0a7ff843d507ce2cca2c3b7e169ee56e28133530 ]

The base baud value reported is supposed to be the highest baud rate
that can be set for a serial port.  The SiFive FU740-C000 SOC's on-chip
UART supports baud rates of up to 1/16 of the input clock rate, which is
the bus clock `tlclk'[1], often at 130MHz in the case of the HiFive
Unmatched board.

However the sifive UART driver reports a fixed value of 115200 instead:

10010000.serial: ttySIF0 at MMIO 0x10010000 (irq = 1, base_baud = 115200) is a SiFive UART v0
10011000.serial: ttySIF1 at MMIO 0x10011000 (irq = 2, base_baud = 115200) is a SiFive UART v0

even though we already support setting higher baud rates, e.g.:

$ tty
/dev/ttySIF1
$ stty speed
230400

The baud base value is computed by the serial core by dividing the UART
clock recorded in `struct uart_port' by 16, which is also the minimum
value of the clock divider supported, so correct the baud base value
reported by setting the UART clock recorded to the input clock rate
rather than 115200:

10010000.serial: ttySIF0 at MMIO 0x10010000 (irq = 1, base_baud = 8125000) is a SiFive UART v0
10011000.serial: ttySIF1 at MMIO 0x10011000 (irq = 2, base_baud = 8125000) is a SiFive UART v0

References:

[1] "SiFive FU740-C000 Manual", v1p3, SiFive, Inc., August 13, 2021,
    Section 16.9 "Baud Rate Divisor Register (div)", pp.143-144

Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Fixes: 1f1496a923b6 ("riscv: Fix sifive serial driver")
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2204291656280.9383@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-14 18:11:52 +02:00
arch MIPS: IP27: Remove incorrect `cpu_has_fpu' override 2022-06-14 18:11:50 +02:00
block block: fix bio_clone_blkg_association() to associate with proper blkcg_gq 2022-06-14 18:11:50 +02:00
certs certs: Trigger creation of RSA module signing key if it's not an RSA key 2021-09-15 09:47:29 +02:00
crypto crypto: cryptd - Protect per-CPU resource by disabling BH. 2022-06-14 18:11:41 +02:00
Documentation dt-bindings: gpio: altera: correct interrupt-cells 2022-06-14 18:11:49 +02:00
drivers serial: sifive: Report actual baud base rather than fixed 115200 2022-06-14 18:11:52 +02:00
fs ocfs2: dlmfs: fix error handling of user_dlm_destroy_lock 2022-06-14 18:11:46 +02:00
include nodemask.h: fix compilation error with GCC12 2022-06-14 18:11:48 +02:00
init Kconfig: add config option for asm goto w/ outputs 2022-06-14 18:11:50 +02:00
ipc ipc/mqueue: use get_tree_nodev() in mqueue_get_tree() 2022-06-14 18:11:41 +02:00
kernel tracing: Fix potential double free in create_var_ref() 2022-06-14 18:11:46 +02:00
lib assoc_array: Fix BUG_ON during garbage collect 2022-06-06 08:33:50 +02:00
LICENSES
mm hugetlb: fix huge_pmd_unshare address update 2022-06-14 18:11:48 +02:00
net mac80211: upgrade passive scan to active scan on DFS channels after beacon rx 2022-06-14 18:11:48 +02:00
samples samples/kretprobes: Fix return value if register_kretprobe() failed 2021-11-17 09:48:39 +01:00
scripts scripts/faddr2line: Fix overlapping text section failures 2022-06-14 18:11:37 +02:00
security efi: Do not import certificates from UEFI Secure Boot for T2 Macs 2022-06-14 18:11:44 +02:00
sound ASoC: rt5514: Fix event generation for "DSP Voice Wake Up" control 2022-06-14 18:11:48 +02:00
tools perf jevents: Fix event syntax error caused by ExtSel 2022-06-14 18:11:44 +02:00
usr
virt KVM: Prevent module exit until all VMs are freed 2022-04-15 14:18:27 +02:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
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COPYING
CREDITS
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Kconfig
MAINTAINERS
Makefile Linux 5.4.197 2022-06-06 08:33:51 +02:00
README

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There are various text files in the Documentation/ subdirectory,
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Please read the Documentation/process/changes.rst file, as it contains the
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