RE: [PATCH] fsl-rio: Correct IECSR register clear value

[Liu Gang-B34182 <B34182@freescale.com>]

Hi, Andrew,

Thanks for your comments.

I think you are right and a more detailed description will be better.

This bug causes the IECSR register clear failure.
In this case, the RETE (retry error threshold exceeded) interrupt will be g=
enerated and cannot be cleared.
So the related ISR may be called persistently.

Thanks again!

Regards,

Liu Gang

-----Original Message-----
From: Andrew Morton [mailto:akpm@linux-foundation.org]=20
Sent: Thursday, August 25, 2011 2:54 AM
To: Liu Gang-B34182
Cc: 'linuxppc-dev@lists.ozlabs.org'; Li Yang-R58472; Gala Kumar-B11780; Zan=
g Roy-R61911
Subject: Re: [PATCH] fsl-rio: Correct IECSR register clear value

On Wed, 24 Aug 2011 09:31:21 +0000
Liu Gang-B34182 <B34182@freescale.com> wrote:

> Hi, Andrew,
>=20
> Thank you for applying the patch "[PATCH] rio: Use discovered bit to test=
 if enumeration is complete "!
>=20
> So far the following patch "[PATCH] fsl-rio: Correct IECSR register clear=
 value " has no comment or response.

Perhaps because you didn't tell anyone what the patch does.

> To: linuxppc-dev@ozlabs.org
> Cc: akpm@linux-foundation.org; Li Yang-R58472; Gala Kumar-B11780; Zang=20
> Roy-R61911; Liu Gang-B34182; Liu Gang-B34182
> Subject: [PATCH] fsl-rio: Correct IECSR register clear value
>=20
> The RETE bit in IECSR is cleared by writing a 1 to it.
>=20
> Signed-off-by: Liu Gang <Gang.Liu@freescale.com>
> ---
>  arch/powerpc/sysdev/fsl_rio.c |    5 +++--
>  1 files changed, 3 insertions(+), 2 deletions(-)
>=20
> diff --git a/arch/powerpc/sysdev/fsl_rio.c=20
> b/arch/powerpc/sysdev/fsl_rio.c index b3fd081..cdd765b 100644
> --- a/arch/powerpc/sysdev/fsl_rio.c
> +++ b/arch/powerpc/sysdev/fsl_rio.c
> @@ -54,6 +54,7 @@
>  #define ODSR_CLEAR		0x1c00
>  #define LTLEECSR_ENABLE_ALL	0xFFC000FC
>  #define ESCSR_CLEAR		0x07120204
> +#define IECSR_CLEAR		0x80000000
> =20
>  #define RIO_PORT1_EDCSR		0x0640
>  #define RIO_PORT2_EDCSR		0x0680
> @@ -1089,11 +1090,11 @@ static void port_error_handler(struct=20
> rio_mport *port, int offset)
> =20
>  	if (offset =3D=3D 0) {
>  		out_be32((u32 *)(rio_regs_win + RIO_PORT1_EDCSR), 0);
> -		out_be32((u32 *)(rio_regs_win + RIO_PORT1_IECSR), 0);
> +		out_be32((u32 *)(rio_regs_win + RIO_PORT1_IECSR), IECSR_CLEAR);
>  		out_be32((u32 *)(rio_regs_win + RIO_ESCSR), ESCSR_CLEAR);
>  	} else {
>  		out_be32((u32 *)(rio_regs_win + RIO_PORT2_EDCSR), 0);
> -		out_be32((u32 *)(rio_regs_win + RIO_PORT2_IECSR), 0);
> +		out_be32((u32 *)(rio_regs_win + RIO_PORT2_IECSR), IECSR_CLEAR);
>  		out_be32((u32 *)(rio_regs_win + RIO_PORT2_ESCSR), ESCSR_CLEAR);
>  	}
>  }

Apparently it fixes some bug.  But because you didn't tell us what the user=
-visible effects of that bug are, I am unable to determine what kernel vers=
ions (if any) the patch should be merged into.