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author | Joshua Scott <joshua.scott@alliedtelesis.co.nz> | 2018-03-16 03:42:00 +0300 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-04-23 11:11:13 +0300 |
commit | b7639b0b15ddd1a4686b0142e70dfb122eefc88f (patch) | |
tree | e2c3f53b29dc09f7a73f99a1f2ad54d539b29362 /arch | |
parent | 63ba1e00f178a4483b473489cadc4eb52a77df2a (diff) | |
download | linux-b7639b0b15ddd1a4686b0142e70dfb122eefc88f.tar.xz |
serial: 8250_dw: Limit dw8250_tx_wait_empty quirk to armada-38x devices
The previous implementation has had a detrimental effect on devices using
high bitrates (bluetooth), as the fifo being non-empty for a single check
would result in a 10 µs delay.
Limit the change to devices with the new "marvell,armada-38x-uart"
compatible string. Also update the code to allow the first 1000 retries
to not perform a delay.
The maximum duration of retries has been increased to cover a worst-case
seen on the Armada 385 SoC. "dmesg ; resize", will fill the buffer with
text to output before doing a resize. At 9600 baud this took up to 13 ms
to flush all characters and avoid some getting lost.
Signed-off-by: Joshua Scott <joshua.scott@alliedtelesis.co.nz>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/arm/boot/dts/armada-38x.dtsi | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/arm/boot/dts/armada-38x.dtsi b/arch/arm/boot/dts/armada-38x.dtsi index 4cc09e43eea2..6916d7532ad2 100644 --- a/arch/arm/boot/dts/armada-38x.dtsi +++ b/arch/arm/boot/dts/armada-38x.dtsi @@ -163,7 +163,7 @@ }; uart0: serial@12000 { - compatible = "snps,dw-apb-uart"; + compatible = "marvell,armada-38x-uart"; reg = <0x12000 0x100>; reg-shift = <2>; interrupts = <GIC_SPI 12 IRQ_TYPE_LEVEL_HIGH>; @@ -173,7 +173,7 @@ }; uart1: serial@12100 { - compatible = "snps,dw-apb-uart"; + compatible = "marvell,armada-38x-uart"; reg = <0x12100 0x100>; reg-shift = <2>; interrupts = <GIC_SPI 13 IRQ_TYPE_LEVEL_HIGH>; |