> -----Original Message-----
> From: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>
> Sent: Monday, May 15, 2023 4:04 AM
> To: linux-wireless@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx; Ping-Ke Shih <pkshih@xxxxxxxxxxx>; tony0620emma@xxxxxxxxx;
> kvalo@xxxxxxxxxx; Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>; Larry Finger
> <Larry.Finger@xxxxxxxxxxxx>; Rudi Heitbaum <rudi@xxxxxxxxxxxx>
> Subject: [PATCH wireless v1] wifi: rtw88: sdio: Always use two consecutive bytes for word operations
>
> The Allwinner sunxi-mmc controller cannot handle word (16 bit)
> transfers. So and sdio_{read,write}w fails with messages like the
> following example using an RTL8822BS (but the same problems were also
> observed with RTL8822CS and RTL8723DS chips):
> rtw_8822bs mmc1:0001:1: Firmware version 27.2.0, H2C version 13
> sunxi-mmc 4021000.mmc: unaligned scatterlist: os f80 length 2
> sunxi-mmc 4021000.mmc: map DMA failed
> rtw_8822bs mmc1:0001:1: sdio read16 failed (0x10230): -22
>
> Use two consecutive single byte accesses for word operations instead. It
> turns out that upon closer inspection this is also what the vendor
> driver does, even though it does have support for sdio_{read,write}w. So
> we can conclude that the rtw88 chips do support word access but only on
> SDIO controllers that also support it. Since there's no way to detect if
> the controller supports word access or not the rtw88 sdio driver
> switches to the easiest approach: avoiding word access.
>
> Reported-by: Larry Finger <Larry.Finger@xxxxxxxxxxxx>
> Closes: https://lore.kernel.org/linux-wireless/527585e5-9cdd-66ed-c3af-6da162f4b720@xxxxxxxxxxxx/
"Closes:" seems not a regular tag. Use "Link: " instead.
> Reported-by: Rudi Heitbaum <rudi@xxxxxxxxxxxx>
Followed by a "Link: " if you have another one.
> Fixes: 65371a3f14e7 ("wifi: rtw88: sdio: Add HCI implementation for SDIO based chipsets")
> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>
> ---
> drivers/net/wireless/realtek/rtw88/sdio.c | 8 --------
> 1 file changed, 8 deletions(-)
>
> diff --git a/drivers/net/wireless/realtek/rtw88/sdio.c b/drivers/net/wireless/realtek/rtw88/sdio.c
> index af0459a79899..06fce7c3adda 100644
> --- a/drivers/net/wireless/realtek/rtw88/sdio.c
> +++ b/drivers/net/wireless/realtek/rtw88/sdio.c
> @@ -87,11 +87,6 @@ static void rtw_sdio_writew(struct rtw_dev *rtwdev, u16 val, u32 addr,
> u8 buf[2];
> int i;
>
> - if (rtw_sdio_use_memcpy_io(rtwdev, addr, 2)) {
> - sdio_writew(rtwsdio->sdio_func, val, addr, err_ret);
> - return;
> - }
> -
> *(__le16 *)buf = cpu_to_le16(val);
>
> for (i = 0; i < 2; i++) {
> @@ -125,9 +120,6 @@ static u16 rtw_sdio_readw(struct rtw_dev *rtwdev, u32 addr, int *err_ret)
> u8 buf[2];
> int i;
>
> - if (rtw_sdio_use_memcpy_io(rtwdev, addr, 2))
> - return sdio_readw(rtwsdio->sdio_func, addr, err_ret);
> -
> for (i = 0; i < 2; i++) {
> buf[i] = sdio_readb(rtwsdio->sdio_func, addr + i, err_ret);
> if (*err_ret)
> --
> 2.40.1
