diff options
| author | Mathieu Othacehe <othacehe@gnu.org> | 2025-05-09 14:19:35 +0200 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-05-12 18:39:38 -0700 |
| commit | c92d6089d8ad7d4d815ebcedee3f3907b539ff1f (patch) | |
| tree | 380ed4f7246f473a2d7f35ec6b2c2cd0bd766848 | |
| parent | 4d64321c4f6faf90b5a3b9f52ee1e7e0eeeff00c (diff) | |
net: cadence: macb: Fix a possible deadlock in macb_halt_tx.
There is a situation where after THALT is set high, TGO stays high as
well. Because jiffies are never updated, as we are in a context with
interrupts disabled, we never exit that loop and have a deadlock.
That deadlock was noticed on a sama5d4 device that stayed locked for days.
Use retries instead of jiffies so that the timeout really works and we do
not have a deadlock anymore.
Fixes: e86cd53afc590 ("net/macb: better manage tx errors")
Signed-off-by: Mathieu Othacehe <othacehe@gnu.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250509121935.16282-1-othacehe@gnu.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | drivers/net/ethernet/cadence/macb_main.c | 19 |
1 files changed, 6 insertions, 13 deletions
diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c index 1fe8ec37491b..e1e8bd2ec155 100644 --- a/drivers/net/ethernet/cadence/macb_main.c +++ b/drivers/net/ethernet/cadence/macb_main.c @@ -997,22 +997,15 @@ static void macb_update_stats(struct macb *bp) static int macb_halt_tx(struct macb *bp) { - unsigned long halt_time, timeout; - u32 status; + u32 status; macb_writel(bp, NCR, macb_readl(bp, NCR) | MACB_BIT(THALT)); - timeout = jiffies + usecs_to_jiffies(MACB_HALT_TIMEOUT); - do { - halt_time = jiffies; - status = macb_readl(bp, TSR); - if (!(status & MACB_BIT(TGO))) - return 0; - - udelay(250); - } while (time_before(halt_time, timeout)); - - return -ETIMEDOUT; + /* Poll TSR until TGO is cleared or timeout. */ + return read_poll_timeout_atomic(macb_readl, status, + !(status & MACB_BIT(TGO)), + 250, MACB_HALT_TIMEOUT, false, + bp, TSR); } static void macb_tx_unmap(struct macb *bp, struct macb_tx_skb *tx_skb, int budget) |