Re: [PATCH v2 3/9] powerpc/powernv: opal_put_chars partial write fix

[Benjamin Herrenschmidt]

On Mon, 2018-04-09 at 15:24 +1000, Nicholas Piggin wrote:
> The intention here is to consume and discard the remaining buffer
> upon error. This works if there has not been a previous partial write.
> If there has been, then total_len is no longer total number of bytes
> to copy. total_len is always "bytes left to copy", so it should be
> added to written bytes.
> 
> This code may not be exercised any more if partial writes will not be
> hit, but this is a small bugfix before a larger change.
> 

Reviewed-by: Benjamin Herrenschmidt 

> Signed-off-by: Nicholas Piggin 
> ---
>  arch/powerpc/platforms/powernv/opal.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/platforms/powernv/opal.c 
> b/arch/powerpc/platforms/powernv/opal.c
> index 516e23de5a3d..87d4c0aa7f64 100644
> --- a/arch/powerpc/platforms/powernv/opal.c
> +++ b/arch/powerpc/platforms/powernv/opal.c
> @@ -388,7 +388,7 @@ int opal_put_chars(uint32_t vtermno, const char *data, 
> int total_len)
>   /* Closed or other error drop */
>   if (rc != OPAL_SUCCESS && rc != OPAL_BUSY &&
>   rc != OPAL_BUSY_EVENT) {
> - written = total_len;
> + written += total_len;
>   break;
>   }
>   if (rc == OPAL_SUCCESS) {

[PATCH v2 3/9] powerpc/powernv: opal_put_chars partial write fix

[Nicholas Piggin]

The intention here is to consume and discard the remaining buffer
upon error. This works if there has not been a previous partial write.
If there has been, then total_len is no longer total number of bytes
to copy. total_len is always "bytes left to copy", so it should be
added to written bytes.

This code may not be exercised any more if partial writes will not be
hit, but this is a small bugfix before a larger change.

Cc: Benjamin Herrenschmidt 
Signed-off-by: Nicholas Piggin 
---
 arch/powerpc/platforms/powernv/opal.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/platforms/powernv/opal.c 
b/arch/powerpc/platforms/powernv/opal.c
index 516e23de5a3d..87d4c0aa7f64 100644
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -388,7 +388,7 @@ int opal_put_chars(uint32_t vtermno, const char *data, int 
total_len)
/* Closed or other error drop */
if (rc != OPAL_SUCCESS && rc != OPAL_BUSY &&
rc != OPAL_BUSY_EVENT) {
-   written = total_len;
+   written += total_len;
break;
}
if (rc == OPAL_SUCCESS) {
-- 
2.17.0