Re: [PATCH] watchdog: sbsa: only use 32-bit accessors

[Guenter Roeck <linux@xxxxxxxxxxxx>]

On 9/3/21 4:21 AM, Jamie Iles wrote:
> SBSA says of the generic watchdog:
>
>    All registers are 32 bits in size and should be accessed using 32-bit
>    reads and writes. If an access size other than 32 bits is used then
>    the results are IMPLEMENTATION DEFINED.
>
> and for qemu, the implementation will only allow 32-bit accesses
> resulting in a synchronous external abort when configuring the watchdog.
> Use lo_hi_* accessors rather than a readq/writeq.
>
> Fixes: abd3ac7902fb ("watchdog: sbsa: Support architecture version 1")
> Signed-off-by: Jamie Iles <quic_jiles@xxxxxxxxxxx>

Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>

> ---
>   drivers/watchdog/sbsa_gwdt.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/watchdog/sbsa_gwdt.c b/drivers/watchdog/sbsa_gwdt.c
> index ee9ff38929eb..6f4319bdbc50 100644
> --- a/drivers/watchdog/sbsa_gwdt.c
> +++ b/drivers/watchdog/sbsa_gwdt.c
> @@ -130,7 +130,7 @@ static u64 sbsa_gwdt_reg_read(struct sbsa_gwdt *gwdt)
>   	if (gwdt->version == 0)
>   		return readl(gwdt->control_base + SBSA_GWDT_WOR);
>   	else
> -		return readq(gwdt->control_base + SBSA_GWDT_WOR);
> +		return lo_hi_readq(gwdt->control_base + SBSA_GWDT_WOR);
>   }
>   
>   static void sbsa_gwdt_reg_write(u64 val, struct sbsa_gwdt *gwdt)
> @@ -138,7 +138,7 @@ static void sbsa_gwdt_reg_write(u64 val, struct sbsa_gwdt *gwdt)
>   	if (gwdt->version == 0)
>   		writel((u32)val, gwdt->control_base + SBSA_GWDT_WOR);
>   	else
> -		writeq(val, gwdt->control_base + SBSA_GWDT_WOR);
> +		lo_hi_writeq(val, gwdt->control_base + SBSA_GWDT_WOR);
>   }
>   
>   /*