Re: [PATCH 09/24] serial: 8250: 8250_bcm7271: fix DMA address truncation to 32 bits

[Ilpo Järvinen]

On Tue, 27 Oct 2026, Greg Kroah-Hartman wrote:

> From: Joshua Rogers <linux@xxxxxxxxx>
> 
> The local variable daddr is declared as u32 but assigned from dma_addr_t
> fields (priv->rx_addr and priv->tx_addr), which are 64-bit on ARM64.
> This silently truncates the upper 32 bits, causing upper_32_bits(daddr)
> to always produce zero when programming the UART DMA descriptor high
> address registers.  Change the type to dma_addr_t to preserve the full
> DMA address.
> 
> Cc: Al Cooper <alcooperx@xxxxxxxxx>
> Cc: Jiri Slaby <jirislaby@xxxxxxxxxx>
> Cc: stable <stable@xxxxxxxxxx>
> Cc: Broadcom internal kernel review list <bcm-kernel-feedback-list@xxxxxxxxxxxx>
> Signed-off-by: Joshua Rogers <linux@xxxxxxxxx>
> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> ---
>  drivers/tty/serial/8250/8250_bcm7271.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/tty/serial/8250/8250_bcm7271.c b/drivers/tty/serial/8250/8250_bcm7271.c
> index 974d9af146a1..4fdd261e55f5 100644
> --- a/drivers/tty/serial/8250/8250_bcm7271.c
> +++ b/drivers/tty/serial/8250/8250_bcm7271.c
> @@ -315,7 +315,7 @@ static int brcmuart_arbitration(struct brcmuart_priv *priv, bool acquire)
>  
>  static void brcmuart_init_dma_hardware(struct brcmuart_priv *priv)
>  {
> -	u32 daddr;
> +	dma_addr_t daddr;
>  	u32 value;
>  	int x;

Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>

-- 
 i.