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ARM: bcm2835: override the HW UART periphid

PATCH New Stephen Warren 2 participants 2 messages May 30, 2013 – Jun 1, 2013

Subsystems (3)
Device tree bindings Broadcom BCM2711/BCM2835 Arm architecture Broadcom BCM281XX/BCM11XXX/BCM216XX Arm architecture
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Stephen Warren

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PATCH 1/1 ARM: bcm2835: override the HW UART periphid

From: Jongsung Kim <[email protected]>

Stephen Warren reported the recent commit 78506f2 (add support for extended FIFO-size of PL011-r1p5) breaks the serial port on the BCM2835 ARM SoC.

A UART compatible with the ARM PL011-r1p5 should have 32-deep FIFOs. The BCM2835 UART just looks like an ARM PL011-r1p5, but has 16-deep FIFOs just like PL011-r1p4 or earlier revisions. As a workaround for this compatibility issue, this patch overrides the HW UART periphid register values with the actually compatible UART periphid 0x00241011 (r1p3 or r1p4).

Reported-by Stephen Warren <[email protected]>
Signed-off-by Jongsung Kim <[email protected]>
Signed-off-by Stephen Warren <[email protected]>

---
This is a fix for v3.10-rc*.

 arch/arm/boot/dts/bcm2835.dtsi |    1 +
 1 file changed, 1 insertion(+)
arch/arm/boot/dts/bcm2835.dtsi +1 -0
index f0052dc..1e12aef 100644
@@ -44,6 +44,7 @@
 			reg = <0x7e201000 0x1000>;
 			interrupts = <2 25>;
 			clock-frequency = <3000000>;
+			arm,primecell-periphid = <0x00241011>;
 		};
 
 		gpio: gpio {
Signature · 1 line
1.7.10.4
Applied
#1 lore raw

PATCH 1/1 ARM: bcm2835: override the HW UART periphid

Quoted 13 lines · Stephen Warren

From: Jongsung Kim <[email protected]>

Stephen Warren reported the recent commit 78506f2 (add support for extended FIFO-size of PL011-r1p5) breaks the serial port on the BCM2835 ARM SoC.

A UART compatible with the ARM PL011-r1p5 should have 32-deep FIFOs. The BCM2835 UART just looks like an ARM PL011-r1p5, but has 16-deep FIFOs just like PL011-r1p4 or earlier revisions. As a workaround for this compatibility issue, this patch overrides the HW UART periphid register values with the actually compatible UART periphid 0x00241011 (r1p3 or r1p4).

Quoted 5 lines
Reported-by Stephen Warren <[email protected]>
Signed-off-by Jongsung Kim <[email protected]>
Signed-off-by Stephen Warren <[email protected]>

---
This is a fix for v3.10-rc*.

Applied.

-Olof