[coreboot-gerrit] Change in coreboot[master]: mb/google/poppy/variants/soraka: Add 10ms reset delay for WCOM device

[Furquan Shaikh (Code Review)]

Furquan Shaikh has uploaded this change for review. ( https://review.coreboot.org/21910


Change subject: mb/google/poppy/variants/soraka: Add 10ms reset delay for WCOM device
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mb/google/poppy/variants/soraka: Add 10ms reset delay for WCOM device

Change 868b3761 (mainboard/google/soraka: Reduce Wacom resume time)
removed the delay after taking device out of reset since it seemed
unnecessary in system resume case (because there is enough time after
taking device out of reset and before communication with device
starts).

However, without the delay, kernel driver runs into issue while
talking to the device during boot-up and runtime
suspend/resume. (Observed this error in dmesg: "i2c_hid
i2c-WCOMCOHO:00: failed to change power setting."). Thus, add 10ms
delay after taking device out of reset. Verified on multiple Soraka
system that with 10ms delay, kernel driver does not run into any issue
talking to the WCOM device during boot-up, runtime suspend/resume and
system suspend/resume.

BUG=b:65358919
TEST=No more errors talking to WCOM device in kernel dmesg.

Change-Id: I485b753cbae4b653e74337e048aea4d26ffdbb81
---
M src/mainboard/google/poppy/variants/soraka/devicetree.cb
1 file changed, 1 insertion(+), 0 deletions(-)



  git pull ssh://review.coreboot.org:29418/coreboot refs/changes/10/21910/1

diff --git a/src/mainboard/google/poppy/variants/soraka/devicetree.cb b/src/mainboard/google/poppy/variants/soraka/devicetree.cb
index f6948d9..1c342a4 100644
--- a/src/mainboard/google/poppy/variants/soraka/devicetree.cb
+++ b/src/mainboard/google/poppy/variants/soraka/devicetree.cb
@@ -281,6 +281,7 @@
 				register "generic.irq" = "ACPI_IRQ_LEVEL_LOW(GPP_E7_IRQ)"
 				register "generic.probed" = "1"
 				register "generic.reset_gpio" = "ACPI_GPIO_OUTPUT_ACTIVE_LOW(GPP_E3)"
+				register "generic.reset_delay_ms" = "10"
 				register "generic.enable_gpio" = "ACPI_GPIO_OUTPUT_ACTIVE_HIGH(GPP_C22)"
 				register "generic.enable_delay_ms" = "1"
 				register "generic.stop_gpio" = "ACPI_GPIO_OUTPUT_ACTIVE_LOW(GPP_E11)"

-- 
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Gerrit-Project: coreboot
Gerrit-Branch: master
Gerrit-MessageType: newchange
Gerrit-Change-Id: I485b753cbae4b653e74337e048aea4d26ffdbb81
Gerrit-Change-Number: 21910
Gerrit-PatchSet: 1
Gerrit-Owner: Furquan Shaikh <furquan at google.com>
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