2019-04-05 19:29:39

by Madhumitha Prabakaran

Subject: [PATCH] Staging: olpc_dcon: Use WARN_ON() instead of BUG_ON()

Use WARN_ON() instead of BUG_ON(), as the WARN_ON() produces a backtrace
without crashing the kernel.

Issue found by checkpatch.pl.

Signed-off-by: Madhumitha Prabakaran <[email protected]>
---
drivers/staging/olpc_dcon/olpc_dcon.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/olpc_dcon/olpc_dcon.c b/drivers/staging/olpc_dcon/olpc_dcon.c
index 6b714f740ac3..900baab70691 100644
--- a/drivers/staging/olpc_dcon/olpc_dcon.c
+++ b/drivers/staging/olpc_dcon/olpc_dcon.c
@@ -138,7 +138,7 @@ static int dcon_bus_stabilize(struct dcon_priv *dcon, int is_powered_down)
}
if (x < 0) {
pr_err("unable to stabilize dcon's smbus, reasserting power and praying.\n");
- BUG_ON(olpc_board_at_least(olpc_board(0xc2)));
+ WARN_ON(olpc_board_at_least(olpc_board(0xc2)));
pm = 0;
olpc_ec_cmd(EC_DCON_POWER_MODE, &pm, 1, NULL, 0);
msleep(100);
--
2.17.1

2019-04-16 11:50:15

by Greg Kroah-Hartman

Subject: Re: [PATCH] Staging: olpc_dcon: Use WARN_ON() instead of BUG_ON()

On Fri, Apr 05, 2019 at 02:28:36PM -0500, Madhumitha Prabakaran wrote:
> Use WARN_ON() instead of BUG_ON(), as the WARN_ON() produces a backtrace
> without crashing the kernel.
>
> Issue found by checkpatch.pl.
>
> Signed-off-by: Madhumitha Prabakaran <[email protected]>
> ---
> drivers/staging/olpc_dcon/olpc_dcon.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/staging/olpc_dcon/olpc_dcon.c b/drivers/staging/olpc_dcon/olpc_dcon.c
> index 6b714f740ac3..900baab70691 100644
> --- a/drivers/staging/olpc_dcon/olpc_dcon.c
> +++ b/drivers/staging/olpc_dcon/olpc_dcon.c
> @@ -138,7 +138,7 @@ static int dcon_bus_stabilize(struct dcon_priv *dcon, int is_powered_down)
> }
> if (x < 0) {
> pr_err("unable to stabilize dcon's smbus, reasserting power and praying.\n");
> - BUG_ON(olpc_board_at_least(olpc_board(0xc2)));
> + WARN_ON(olpc_board_at_least(olpc_board(0xc2)));

If this change was as simple as this, we would have done it already :(

You have to properly handle this error that used to crash the system, by
properly correctly for it and continuing on. You can't just log it and
keep on going, right?

thanks,

greg k-h