RE: [PATCH v2] wifi: rtlwifi: rtl_usb: Use sync register writes

[Ping-Ke Shih <pkshih@realtek.com>]

> -----Original Message-----
> From: Bitterblue Smith <rtl8821cerfe2@gmail.com>
> Sent: Wednesday, January 10, 2024 9:47 PM
> To: linux-wireless@vger.kernel.org
> Cc: Ping-Ke Shih <pkshih@realtek.com>; Larry Finger <Larry.Finger@lwfinger.net>
> Subject: [PATCH v2] wifi: rtlwifi: rtl_usb: Use sync register writes
> 
> Currently rtl_usb performs register writes using the async
> usb_submit_urb() function. This appears to work fine for the RTL8192CU,
> but the RTL8192DU (soon to be supported by rtlwifi) has a problem:
> it transmits everything at the 1M rate in the 2.4 GHz band. (The 5 GHz
> band is still untested.)
> 
> With this patch, rtl_usb performs the register writes using the
> synchronous usb_control_msg() function, and the RTL8192DU works
> normally. The RTL8192CU still works.
> 
> The vendor drivers use the async writes in only one function,
> rtl8192du_trigger_gpio_0 / rtl8192cu_trigger_gpio_0, which probably
> doesn't even run in real life. They use sync writes everywhere else.
> 
> Also, remove "sync" and "async" from the names of the members of
> struct rtl_io to avoid confusion:
> 
> write{8,16,32}_async -> write{8,16,32}
>  read{8,16,32}_sync  ->  read{8,16,32}
> 
> Signed-off-by: Bitterblue Smith <rtl8821cerfe2@gmail.com>

Acked-by: Ping-Ke Shih <pkshih@realtek.com>

> ---
> v2:
>  - Rename the members of struct rtl_io.
> ---
>  drivers/net/wireless/realtek/rtlwifi/pci.c  |  12 +-
>  drivers/net/wireless/realtek/rtlwifi/usb.c  | 163 ++++++--------------
>  drivers/net/wireless/realtek/rtlwifi/wifi.h |  30 ++--
>  3 files changed, 66 insertions(+), 139 deletions(-)
> 

[...]

> @@ -114,18 +51,15 @@ static int _usbctrl_vendorreq_sync_read(struct usb_device *udev, u8 request,
>         } while (++vendorreq_times < MAX_USBCTRL_VENDORREQ_TIMES);
> 
>         if (status < 0 && count++ < 4)
> -               pr_err("reg 0x%x, usbctrl_vendorreq TimeOut! status:0x%x value=0x%x\n",
> -                      value, status, *(u32 *)pdata);
> -       return status;
> +               pr_err("reg 0x%x, usbctrl_vendorreq TimeOut! status:0x%x value=0x%x reqtype=0x%x\n",

nit: Since you touch this, would you like to use dev_err() instead?

> +                      value, status, *(u32 *)pdata, reqtype);
>  }
> 

[...]