Bug#803987: firmware-realtek: Very weak signal on RTL8723BE adaptor
On 2015-11-03 21:48 +0100, Antonio Peiro Saez wrote:
> Package: firmware-realtek
> Version: 20151018-2
> Severity: important
>
> After a clean installation of Debian 8.2 in a disk partition of my
> laptop the Realtek wireless network adapter, and the Realtek ethernet
> controller needed the installation of the nonfree firmware.
>
> antonio@BB-8:~$ uname -a
> Linux BB-8 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt11-1+deb8u4 (2015-09-19) x86_64 GNU/Linux
> antonio@BB-8:~$ lspci | grep Realtek
> 02:00.0 Network controller: Realtek Semiconductor Co., Ltd. RTL8723BE PCIe Wireless Network Adapter
> 03:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8101E/RTL8102E PCI Express Fast Ethernet controller (rev 07)
>
> The installation of the firmware-realtek 0.43 package included with
> the Debian distribution wasn't a problem.
>
> The ethernet controller works fine but the Wifi adapter not. It is a
> very strange situation because de wireless network adapter only catch
> the router signal if the laptop is situated at less than 1 meter from
> the router antenna.
This is not really a problem of the firmware, but rather of the
hardware. Commit c18d8f5095715c56bb3cd9cba64242542632054b in the Linux
kernel tree gives an explanation:
,----
| $ git show c18d8f5095715c56bb3cd9cba64242542632054b
| commit c18d8f5095715c56bb3cd9cba64242542632054b
| Author: Larry Finger <Larry.Finger@lwfinger.net>
| Date: Wed Mar 16 13:33:34 2016 -0500
|
| rtlwifi: rtl8723be: Add antenna select module parameter
|
| A number of new laptops have been delivered with only a single antenna.
| In principle, this is OK; however, a problem arises when the on-board
| EEPROM is programmed to use the other antenna connection. The option
| of opening the computer and moving the connector is not always possible
| as it will void the warranty in some cases. In addition, this solution
| breaks the Windows driver when the box dual boots Linux and Windows.
|
| A fix involving a new module parameter has been developed. This commit
| adds the new parameter and implements the changes needed for the driver.
|
| Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
| Cc: Stable <stable@vger.kernel.org> [V4.0+]
| Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
`----
With this commit (which went into Linux 4.7 and was subsequently
cherry-picked for the 4.x stable kernels), the rtl8723be module got a
new parameter ant_sel which you can set to 0 (the default), 1 or 2.
Recently I got myself a laptop with a RTL8723BE wireless adapter, and
with "modprobe rtl8723be ant_sel=1" the WiFi works perfectly, without
that parameter, "iwlist scan" would not report anything.
Cheers,
Sven
Reply to: