linux-kernel - [PATCH V2 net] net: qca_spi: Avoid high load if QCA7000 is not available

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Message-Id: <20230614210656.6264-1-stefan.wahren@i2se.com>
Date:   Wed, 14 Jun 2023 23:06:56 +0200
From:   Stefan Wahren <stefan.wahren@...e.com>
To:     "David S . Miller" <davem@...emloft.net>,
        Eric Dumazet <edumazet@...gle.com>,
        Jakub Kicinski <kuba@...nel.org>,
        Paolo Abeni <pabeni@...hat.com>
Cc:     Stefan Wahren <stefan.wahren@...rgebyte.com>,
        Simon Horman <simon.horman@...igine.com>,
        netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
        Stefan Wahren <stefan.wahren@...e.com>
Subject: [PATCH V2 net] net: qca_spi: Avoid high load if QCA7000 is not available

In case the QCA7000 is not available via SPI (e.g. in reset),
the driver will cause a high load. The reason for this is
that the synchronization is never finished and schedule()
is never called. Since the synchronization is not timing
critical, it's safe to drop this from the scheduling condition.

Signed-off-by: Stefan Wahren <stefan.wahren@...e.com>
Fixes: 291ab06ecf67 ("net: qualcomm: new Ethernet over SPI driver for QCA7000")
---

Changes in V2:
- send from different account which doesn't break the patch

 drivers/net/ethernet/qualcomm/qca_spi.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/qualcomm/qca_spi.c b/drivers/net/ethernet/qualcomm/qca_spi.c
index bba1947792ea16..90f18ea4c28ba1 100644
--- a/drivers/net/ethernet/qualcomm/qca_spi.c
+++ b/drivers/net/ethernet/qualcomm/qca_spi.c
@@ -582,8 +582,7 @@ qcaspi_spi_thread(void *data)
 	while (!kthread_should_stop()) {
 		set_current_state(TASK_INTERRUPTIBLE);
 		if ((qca->intr_req == qca->intr_svc) &&
-		    (qca->txr.skb[qca->txr.head] == NULL) &&
-		    (qca->sync == QCASPI_SYNC_READY))
+		    !qca->txr.skb[qca->txr.head])
 			schedule();
 
 		set_current_state(TASK_RUNNING);