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authorLukas Wunner <lukas@wunner.de>2021-12-28 18:22:00 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-12-30 13:23:44 +0100
commitb4a29b94804c4774f22555651296b838df6ec0e4 (patch)
tree941ce02678fe2d72628c8bd9d4428b1ce100f985 /include/linux/serial_8250.h
parentd3b3404df318504ec084213ab1065b73f49b0f1d (diff)
serial: 8250: Move Alpha-specific quirk out of the core
struct uart_8250_port contains mcr_mask and mcr_force members whose sole purpose is to work around an Alpha-specific quirk. This code doesn't belong in the core where it is executed by everyone else, so move it to a proper ->set_mctrl callback which is used on the affected Alpha machine only. The quirk was introduced in January 1995: https://git.kernel.org/pub/scm/linux/kernel/git/history/history.git/diff/drivers/char/serial.c?h=1.1.83 The members in struct uart_8250_port were added in 2002: https://git.kernel.org/history/history/c/4524aad27854 The quirk applies to non-PCI Alphas and arch/alpha/Kconfig specifies "select FORCE_PCI if !ALPHA_JENSEN". So apparently the only affected machine is the EISA-based Jensen that Linus was working on back then: https://lore.kernel.org/all/CAHk-=wj1JWZ3sCrGz16nxEj7=0O+srMg6Ah3iPTDXSPKEws_SA@mail.gmail.com/ Up until now the quirk is not applied unless CONFIG_PCI is disabled. If users forget to do that or run a generic Alpha kernel, the serial ports aren't usable on Jensen. Avoid by confining the quirk to CONFIG_ALPHA_JENSEN instead of !CONFIG_PCI. On generic Alpha kernels, auto-detect at runtime whether the quirk needs to be applied. Cc: Russell King <rmk+kernel@armlinux.org.uk> Cc: Ulrich Teichert <krypton@ulrich-teichert.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/b83d069cb516549b8a5420e097bb6bdd806f36fc.1640695609.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/linux/serial_8250.h')
-rw-r--r--include/linux/serial_8250.h2
1 files changed, 0 insertions, 2 deletions
diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h
index 5db211f43b29..ff84a3ed10ea 100644
--- a/include/linux/serial_8250.h
+++ b/include/linux/serial_8250.h
@@ -104,8 +104,6 @@ struct uart_8250_port {
unsigned char ier;
unsigned char lcr;
unsigned char mcr;
- unsigned char mcr_mask; /* mask of user bits */
- unsigned char mcr_force; /* mask of forced bits */
unsigned char cur_iotype; /* Running I/O type */
unsigned int rpm_tx_active;
unsigned char canary; /* non-zero during system sleep