Re: [PATCH 6/9] ppc440_bamboo.c: handle clock freq read error in load_device_tree

[Cédric Le Goater]

On 6/30/22 21:42, Daniel Henrique Barboza wrote:
> Let's put the default clock and timebase freq value in macros for better
> readability.  Use PPC440EP_CLOCK_FREQ as the default value of
> 'clock_freq' if kvmppc_get_clockfreq() throws an error.
>
> Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
> ---
>   hw/ppc/ppc440_bamboo.c | 17 ++++++++++++++---
>   1 file changed, 14 insertions(+), 3 deletions(-)
>
> diff --git a/hw/ppc/ppc440_bamboo.c b/hw/ppc/ppc440_bamboo.c
> index d23f881d9d..6318112393 100644
> --- a/hw/ppc/ppc440_bamboo.c
> +++ b/hw/ppc/ppc440_bamboo.c
> @@ -50,6 +50,10 @@
>   
>   #define PPC440EP_SDRAM_NR_BANKS 4
>   
> +#define PPC440EP_TB_FREQ        400000000
> +#define PPC440EP_CLOCK_FREQ     400000000
> +
> +
>   static const ram_addr_t ppc440ep_sdram_bank_sizes[] = {
>       256 * MiB, 128 * MiB, 64 * MiB, 32 * MiB, 16 * MiB, 8 * MiB, 0
>   };
> @@ -67,8 +71,8 @@ static int bamboo_load_device_tree(hwaddr addr,
>       char *filename;
>       int fdt_size;
>       void *fdt;
> -    uint32_t tb_freq = 400000000;
> -    uint32_t clock_freq = 400000000;
> +    uint32_t tb_freq = PPC440EP_TB_FREQ;
> +    uint32_t clock_freq = PPC440EP_CLOCK_FREQ;
>   
>       filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, BINARY_DEVICE_TREE_FILE);
>       if (!filename) {
> @@ -106,8 +110,15 @@ static int bamboo_load_device_tree(hwaddr addr,
>        * directly access the timebase without host involvement, we must expose
>        * the correct frequencies. */
>       if (kvm_enabled()) {
> +        Error *local_err = NULL;
> +
>           tb_freq = kvmppc_get_tbfreq();
> -        clock_freq = kvmppc_get_clockfreq(NULL);
> +        clock_freq = kvmppc_get_clockfreq(&local_err);
> +
> +        /* Use default clock if we're unable to read it from the DT */
> +        if (local_err) {

may be report the error to the user ?

> +            clock_freq = PPC440EP_CLOCK_FREQ;
> +        }
>       }
>   
>       qemu_fdt_setprop_cell(fdt, "/cpus/cpu@0", "clock-frequency",