| Message ID | 20210415230234.14895-1-ilya.lipnitskiy@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net-next] net: ethernet: mediatek: ppe: fix busy wait loop | expand |
| Context | Check | Description |
|---|---|---|
| netdev/cover_letter | success | Link |
| netdev/fixes_present | success | Link |
| netdev/patch_count | success | Link |
| netdev/tree_selection | success | Clearly marked for net-next |
| netdev/subject_prefix | success | Link |
| netdev/cc_maintainers | success | CCed 11 of 11 maintainers |
| netdev/source_inline | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Link |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/build_32bit | success | Errors and warnings before: 0 this patch: 0 |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/verify_fixes | success | Link |
| netdev/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 8 lines checked |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 0 this patch: 0 |
| netdev/header_inline | success | Link |
On Thu, Apr 15, 2021 at 04:02:34PM -0700, Ilya Lipnitskiy wrote: > The intention is for the loop to timeout if the body does not succeed. > The current logic calls time_is_before_jiffies(timeout) which is false > until after the timeout, so the loop body never executes. > > time_is_after_jiffies(timeout) will return true until timeout is less > than jiffies, which is the intended behavior here. > > Fixes: ba37b7caf1ed ("net: ethernet: mtk_eth_soc: add support for initializing the PPE") > Signed-off-by: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com> > Cc: Felix Fietkau <nbd@nbd.name> > --- > drivers/net/ethernet/mediatek/mtk_ppe.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/net/ethernet/mediatek/mtk_ppe.c b/drivers/net/ethernet/mediatek/mtk_ppe.c > index 71e1ccea6e72..af3c266297aa 100644 > --- a/drivers/net/ethernet/mediatek/mtk_ppe.c > +++ b/drivers/net/ethernet/mediatek/mtk_ppe.c > @@ -46,7 +46,7 @@ static int mtk_ppe_wait_busy(struct mtk_ppe *ppe) > { > unsigned long timeout = jiffies + HZ; > > - while (time_is_before_jiffies(timeout)) { > + while (time_is_after_jiffies(timeout)) { > if (!(ppe_r32(ppe, MTK_PPE_GLO_CFG) & MTK_PPE_GLO_CFG_BUSY)) > return 0; Maybe see is iopoll.h can be used. Andrew > > -- > 2.31.1 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
diff --git a/drivers/net/ethernet/mediatek/mtk_ppe.c b/drivers/net/ethernet/mediatek/mtk_ppe.c index 71e1ccea6e72..af3c266297aa 100644 --- a/drivers/net/ethernet/mediatek/mtk_ppe.c +++ b/drivers/net/ethernet/mediatek/mtk_ppe.c @@ -46,7 +46,7 @@ static int mtk_ppe_wait_busy(struct mtk_ppe *ppe) { unsigned long timeout = jiffies + HZ; - while (time_is_before_jiffies(timeout)) { + while (time_is_after_jiffies(timeout)) { if (!(ppe_r32(ppe, MTK_PPE_GLO_CFG) & MTK_PPE_GLO_CFG_BUSY)) return 0;
The intention is for the loop to timeout if the body does not succeed. The current logic calls time_is_before_jiffies(timeout) which is false until after the timeout, so the loop body never executes. time_is_after_jiffies(timeout) will return true until timeout is less than jiffies, which is the intended behavior here. Fixes: ba37b7caf1ed ("net: ethernet: mtk_eth_soc: add support for initializing the PPE") Signed-off-by: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com> Cc: Felix Fietkau <nbd@nbd.name> --- drivers/net/ethernet/mediatek/mtk_ppe.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)