On 08/07/2024 12:19, Ping-Ke Shih wrote:
> Bitterblue Smith <rtl8821cerfe2@xxxxxxxxx> wrote:
>> The Realtek wifi 5 devices which support USB 3 are weird: when first
>> plugged in, they pretend to be USB 2. The driver needs to send some
>> commands to the device, which make it disappear and come back as a
>> USB 3 device.
>>
>> Implement the required commands in rtw88.
>>
>> When a USB 3 device is plugged into a USB 2 port, rtw88 will try to
>> switch it to USB 3 mode only once. The device will disappear and come
>> back still in USB 2 mode, of course.
>>
>> Some people experience heavy interference in the 2.4 GHz band in
>> USB 3 mode, so add a module parameter switch_usb_mode with the
>> default value 1 to let people disable the switching.
>>
>> Signed-off-by: Bitterblue Smith <rtl8821cerfe2@xxxxxxxxx>
>> ---
>> A later patch will add the function rtw_usb_switch_mode_old() for the
>> older chips RTL8812AU and RTL8814AU.
>
> [...]
>
>> diff --git a/drivers/net/wireless/realtek/rtw88/usb.c b/drivers/net/wireless/realtek/rtw88/usb.c
>> index a55ca5a24227..a59e52a0da10 100644
>> --- a/drivers/net/wireless/realtek/rtw88/usb.c
>> +++ b/drivers/net/wireless/realtek/rtw88/usb.c
>> @@ -14,6 +14,11 @@
>> #include "ps.h"
>> #include "usb.h"
>>
>> +static bool rtw_switch_usb_mode = true;
>> +module_param_named(switch_usb_mode, rtw_switch_usb_mode, bool, 0644);
>> +MODULE_PARM_DESC(switch_usb_mode,
>> + "Set to Y to switch to USB 3 mode (default: Y)");
>> +
>
> I feel we should say "Set to N to disable switching USB 3 mode to avoid
> potential interference in the 2.4 GHz" like your commit message. That could
> be helpful to users.
>
Sounds good.
>> #define RTW_USB_MAX_RXQ_LEN 512
>>
>> struct rtw_usb_txcb {
>
> [...]
>
>> @@ -896,6 +972,14 @@ int rtw_usb_probe(struct usb_interface *intf, const struct usb_device_id *id)
>> goto err_destroy_rxwq;
>> }
>>
>> + ret = rtw_usb_switch_mode(rtwdev);
>> + if (ret) {
>> + /* Not a fail, but we do need to skip rtw_register_hw. */
>> + rtw_info(rtwdev, "switching to USB 3 mode\n");
>
> All logs in this patches should be rtw_dbg(), because these messages are not
> important to users.
>
Okay, I will add RTW_DBG_USB to enum rtw_debug_mask.
>
>> + ret = 0;
>> + goto err_destroy_rxwq;
>> + }
>> +
>> ret = rtw_register_hw(rtwdev, rtwdev->hw);
>> if (ret) {
>> rtw_err(rtwdev, "failed to register hw\n");
>> --
>> 2.45.1
>
