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arm: mvebu: Reduce reg-io-width with UARTs
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Setting the reg-io-width to 1 byte represents more accurate
description of the HW.

This will fix an issue where UART driver causes kernel
panic during bootup. Gregory CLEMENT traced the issue to
autoconfig() in 8250.c, where the existence of FIFO is
checked from UART_IIR register. The register is now read as
32-bit value as the reg-io-width is set to 4-bytes. The
retuned value seems to contain bogus data for bits 31:8,
causing the issue.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: Gregory CLEMENT <gregory.clement@free-electrons.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
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Heikki Krogerus authored and Jason Cooper committed Mar 8, 2013
1 parent 85c0c13 commit e366154
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Showing 2 changed files with 4 additions and 4 deletions.
4 changes: 2 additions & 2 deletions arch/arm/boot/dts/armada-370-xp.dtsi
Original file line number Diff line number Diff line change
Expand Up @@ -54,15 +54,15 @@
reg = <0xd0012000 0x100>;
reg-shift = <2>;
interrupts = <41>;
reg-io-width = <4>;
reg-io-width = <1>;
status = "disabled";
};
serial@d0012100 {
compatible = "snps,dw-apb-uart";
reg = <0xd0012100 0x100>;
reg-shift = <2>;
interrupts = <42>;
reg-io-width = <4>;
reg-io-width = <1>;
status = "disabled";
};

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4 changes: 2 additions & 2 deletions arch/arm/boot/dts/armada-xp.dtsi
Original file line number Diff line number Diff line change
Expand Up @@ -46,15 +46,15 @@
reg = <0xd0012200 0x100>;
reg-shift = <2>;
interrupts = <43>;
reg-io-width = <4>;
reg-io-width = <1>;
status = "disabled";
};
serial@d0012300 {
compatible = "snps,dw-apb-uart";
reg = <0xd0012300 0x100>;
reg-shift = <2>;
interrupts = <44>;
reg-io-width = <4>;
reg-io-width = <1>;
status = "disabled";
};

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