qca_spi: Make interrupt remembering atomic

The whole mechanism to remember occurred SPI interrupts is not atomic,
which could lead to unexpected behavior. So fix this by using atomic bit
operations instead.

Fixes: 291ab06ecf67 ("net: qualcomm: new Ethernet over SPI driver for QCA7000")
Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Link: https://lore.kernel.org/r/20240614145030.7781-1-wahrenst@gmx.net
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/drivers/net/ethernet/qualcomm/qca_debug.c b/drivers/net/ethernet/qualcomm/qca_debug.c
index ff3b89e9028e9b72039a692955c5aa83bfa11a13..ad06da0fdaa04a29b0a2d2f53825561ab7df2d49 100644 (file)
--- a/drivers/net/ethernet/qualcomm/qca_debug.c
+++ b/drivers/net/ethernet/qualcomm/qca_debug.c
@@ -98,10 +98,8 @@ qcaspi_info_show(struct seq_file *s, void *what)
 
        seq_printf(s, "IRQ              : %d\n",
                   qca->spi_dev->irq);
-       seq_printf(s, "INTR REQ         : %u\n",
-                  qca->intr_req);
-       seq_printf(s, "INTR SVC         : %u\n",
-                  qca->intr_svc);
+       seq_printf(s, "INTR             : %lx\n",
+                  qca->intr);
 
        seq_printf(s, "SPI max speed    : %lu\n",
                   (unsigned long)qca->spi_dev->max_speed_hz);

diff --git a/drivers/net/ethernet/qualcomm/qca_spi.c b/drivers/net/ethernet/qualcomm/qca_spi.c
index 5799ecc88a875b70752dce3a9a1b405e9e836e3a..8f7ce6b51a1c9b42f5cf8d120a0f855bc6828643 100644 (file)
--- a/drivers/net/ethernet/qualcomm/qca_spi.c
+++ b/drivers/net/ethernet/qualcomm/qca_spi.c
@@ -35,6 +35,8 @@
 
 #define MAX_DMA_BURST_LEN 5000
 
+#define SPI_INTR 0
+
 /*   Modules parameters     */
 #define QCASPI_CLK_SPEED_MIN 1000000
 #define QCASPI_CLK_SPEED_MAX 16000000
@@ -579,14 +581,14 @@ qcaspi_spi_thread(void *data)
                        continue;
                }
 
-               if ((qca->intr_req == qca->intr_svc) &&
+               if (!test_bit(SPI_INTR, &qca->intr) &&
                    !qca->txr.skb[qca->txr.head])
                        schedule();
 
                set_current_state(TASK_RUNNING);
 
-               netdev_dbg(qca->net_dev, "have work to do. int: %d, tx_skb: %p\n",
-                          qca->intr_req - qca->intr_svc,
+               netdev_dbg(qca->net_dev, "have work to do. int: %lu, tx_skb: %p\n",
+                          qca->intr,
                           qca->txr.skb[qca->txr.head]);
 
                qcaspi_qca7k_sync(qca, QCASPI_EVENT_UPDATE);
@@ -600,8 +602,7 @@ qcaspi_spi_thread(void *data)
                        msleep(QCASPI_QCA7K_REBOOT_TIME_MS);
                }
 
-               if (qca->intr_svc != qca->intr_req) {
-                       qca->intr_svc = qca->intr_req;
+               if (test_and_clear_bit(SPI_INTR, &qca->intr)) {
                        start_spi_intr_handling(qca, &intr_cause);
 
                        if (intr_cause & SPI_INT_CPU_ON) {
@@ -663,7 +664,7 @@ qcaspi_intr_handler(int irq, void *data)
 {
        struct qcaspi *qca = data;
 
-       qca->intr_req++;
+       set_bit(SPI_INTR, &qca->intr);
        if (qca->spi_thread)
                wake_up_process(qca->spi_thread);
 
@@ -679,8 +680,7 @@ qcaspi_netdev_open(struct net_device *dev)
        if (!qca)
                return -EINVAL;
 
-       qca->intr_req = 1;
-       qca->intr_svc = 0;
+       set_bit(SPI_INTR, &qca->intr);
        qca->sync = QCASPI_SYNC_UNKNOWN;
        qcafrm_fsm_init_spi(&qca->frm_handle);
 

diff --git a/drivers/net/ethernet/qualcomm/qca_spi.h b/drivers/net/ethernet/qualcomm/qca_spi.h
index d59cb2352ceecc3c65bbf4bc70edcb4b44f67510..8f4808695e82069c6c10f598ac982bb89d7ac5a0 100644 (file)
--- a/drivers/net/ethernet/qualcomm/qca_spi.h
+++ b/drivers/net/ethernet/qualcomm/qca_spi.h
@@ -81,8 +81,7 @@ struct qcaspi {
        struct qcafrm_handle frm_handle;
        struct sk_buff *rx_skb;
 
-       unsigned int intr_req;
-       unsigned int intr_svc;
+       unsigned long intr;
        u16 reset_count;
 
 #ifdef CONFIG_DEBUG_FS