APPLIED: [Artful/linux-oem][PATCH] fixing a wifi hw blocked issue on a lenovo laptop

Khaled Elmously khalid.elmously at canonical.com
Sat Feb 3 01:51:13 UTC 2018


(Forgot to add "APPLIED" to the subject)

On 2018-01-17 10:01:01 , Hui Wang wrote:
> BugLink: http://bugs.launchpad.net/bugs/1743672
> 
> On this machine, we can not find wifi enable/disable hw switch from the laptop,
> but the wifi driver always reports that the wifi radio is hard blocked by switch.
> 
> $ rfkill list
> 0: hci0: Bluetooth
> 	Soft blocked: no
> 	Hard blocked: no
> 1: phy0: Wireless LAN
> 	Soft blocked: no
> 	Hard blocked: yes
> 
> [Impact]
> Both Artful and OEM kernel has this issue, but linux-4.14-rc1 does not have this issue.
> 
> I tried to copy whole wifi driver from 4.14-rc1 to OEM kernel, but can't fix this issue.
> Since it is EC to handle the function key or hw switch on laptops, i tried to copy EC
> driver to OEM kernel, this issue is fixed. Then bisect on the EC driver, I found this
> patch fixed the issue.
> 
> Without this patch, the EC driver will find EC device from ECDT table first rather than
> DSDT table first, then the wifi radio is always reported hw blocked by EC driver. After
> applying this patch, the EC driver will find the EC device from DSDT table first, and
> initialze the EC driver according to the definiton in the DSDT table, then the radio
> switch can be reported correctly (under Windows 10, it is reported to be unblcoked).
> 
> [Test Case]
> boot the system and connnect the wifi with AP, network works well.
> 
> [Fix]
> Backport the uptream patch, and the Bionic kenel already had this patch.
> 
> [Regression Potential]
> I tested on several lenovo laptops and Dell laptops, they all worked well as before.
> I checked the dmesg, there is no error message about EC or EC driver.
> And this patch is cherry-picked from upstream, the possibility of regression is very low.
> 
> 
> Lv Zheng (1):
>   ACPI: EC: Fix possible issues related to EC initialization order
> 
>  drivers/acpi/ec.c | 25 ++++++++++++++++---------
>  1 file changed, 16 insertions(+), 9 deletions(-)
> 
> -- 
> 2.7.4
> 
> 
> -- 
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