Re: [PATCH 02/13] powerpc/rtasd: use correct OF API for event scan rate

From: Andrew Donnellan <ajd@linux.ibm.com>
To: Nathan Lynch <nathanl@linux.ibm.com>, linuxppc-dev@lists.ozlabs.org
Cc: tyreld@linux.ibm.com, nnac123@linux.ibm.com,
	ldufour@linux.ibm.com, npiggin@gmail.com
Subject: Re: [PATCH 02/13] powerpc/rtasd: use correct OF API for event scan rate
Date: Tue, 22 Nov 2022 13:39:32 +1100	[thread overview]
Message-ID: <75044c47f1fa65ed1b9338022b653df0b80b8a3c.camel@linux.ibm.com> (raw)
In-Reply-To: <20221118150751.469393-3-nathanl@linux.ibm.com>

On Fri, 2022-11-18 at 09:07 -0600, Nathan Lynch wrote:
> rtas_token() should be used only for properties that are RTAS
> function
> tokens. "rtas-event-scan-rate" does not contain a function token, but
> it
> has the same size/format as token properties so reading it with
> rtas_token() happens to work.
> 
> Convert to of_property_read_u32().
> 
> Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>

Did a quick grep for the other OF device tree properties listed in R1-
7.2.6-3 of PAPR to see if we make the same mistake elsewhere, and the
only other one is rtas-error-log-max which I see you clean up later in
the series.

Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>

> ---
>  arch/powerpc/kernel/rtasd.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/powerpc/kernel/rtasd.c
> b/arch/powerpc/kernel/rtasd.c
> index 5270b450bbde..cc56ac6ba4b0 100644
> --- a/arch/powerpc/kernel/rtasd.c
> +++ b/arch/powerpc/kernel/rtasd.c
> @@ -9,6 +9,7 @@
>  #include <linux/errno.h>
>  #include <linux/sched.h>
>  #include <linux/kernel.h>
> +#include <linux/of.h>
>  #include <linux/poll.h>
>  #include <linux/proc_fs.h>
>  #include <linux/init.h>
> @@ -499,6 +500,8 @@ EXPORT_SYMBOL_GPL(rtas_cancel_event_scan);
>  
>  static int __init rtas_event_scan_init(void)
>  {
> +       int err;
> +
>         if (!machine_is(pseries) && !machine_is(chrp))
>                 return 0;
>  
> @@ -509,8 +512,8 @@ static int __init rtas_event_scan_init(void)
>                 return -ENODEV;
>         }
>  
> -       rtas_event_scan_rate = rtas_token("rtas-event-scan-rate");
> -       if (rtas_event_scan_rate == RTAS_UNKNOWN_SERVICE) {
> +       err = of_property_read_u32(rtas.dev, "rtas-event-scan-rate",
> &rtas_event_scan_rate);
> +       if (err) {
>                 printk(KERN_ERR "rtasd: no rtas-event-scan-rate on
> system\n");
>                 return -ENODEV;
>         }

-- 
Andrew Donnellan    OzLabs, ADL Canberra
ajd@linux.ibm.com   IBM Australia Limited