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Subject[patch V2 06/36] net: cxgb3: Cleanup in_interrupt() usage
From: Thomas Gleixner <tglx@linutronix.de>

t3_sge_stop() is called from task context and from error handlers in
interrupt context. It relies on in_interrupt() to differentiate the
contexts.

in_interrupt() is deprecated as it is ill defined and does not provide what
it suggests.

Instead of replacing it with some other construct, simply split the
function into t3_sge_stop_dma(), which can be called from any context, and
t3_sge_stop() which can be only called from task context.

This has the advantage that any bogus invocation of t3_sge_stop() from
wrong contexts can be caught by debug kernels instead of being papered over
by the conditional.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>


---
drivers/net/ethernet/chelsio/cxgb3/adapter.h | 1
drivers/net/ethernet/chelsio/cxgb3/cxgb3_main.c | 2 -
drivers/net/ethernet/chelsio/cxgb3/sge.c | 44 ++++++++++++++----------
3 files changed, 29 insertions(+), 18 deletions(-)

--- a/drivers/net/ethernet/chelsio/cxgb3/adapter.h
+++ b/drivers/net/ethernet/chelsio/cxgb3/adapter.h
@@ -313,6 +313,7 @@ void t3_os_link_fault(struct adapter *ad
void t3_os_link_fault_handler(struct adapter *adapter, int port_id);

void t3_sge_start(struct adapter *adap);
+void t3_sge_stop_dma(struct adapter *adap);
void t3_sge_stop(struct adapter *adap);
void t3_start_sge_timers(struct adapter *adap);
void t3_stop_sge_timers(struct adapter *adap);
--- a/drivers/net/ethernet/chelsio/cxgb3/cxgb3_main.c
+++ b/drivers/net/ethernet/chelsio/cxgb3/cxgb3_main.c
@@ -2996,7 +2996,7 @@ void t3_fatal_err(struct adapter *adapte
unsigned int fw_status[4];

if (adapter->flags & FULL_INIT_DONE) {
- t3_sge_stop(adapter);
+ t3_sge_stop_dma(adapter);
t3_write_reg(adapter, A_XGM_TX_CTRL, 0);
t3_write_reg(adapter, A_XGM_RX_CTRL, 0);
t3_write_reg(adapter, XGM_REG(A_XGM_TX_CTRL, 1), 0);
--- a/drivers/net/ethernet/chelsio/cxgb3/sge.c
+++ b/drivers/net/ethernet/chelsio/cxgb3/sge.c
@@ -3271,30 +3271,40 @@ void t3_sge_start(struct adapter *adap)
}

/**
- * t3_sge_stop - disable SGE operation
+ * t3_sge_stop_dma - Disable SGE DMA engine operation
* @adap: the adapter
*
- * Disables the DMA engine. This can be called in emeregencies (e.g.,
- * from error interrupts) or from normal process context. In the latter
- * case it also disables any pending queue restart tasklets. Note that
- * if it is called in interrupt context it cannot disable the restart
- * tasklets as it cannot wait, however the tasklets will have no effect
- * since the doorbells are disabled and the driver will call this again
- * later from process context, at which time the tasklets will be stopped
- * if they are still running.
+ * Can be invoked from interrupt context e.g. error handler.
+ *
+ * Note that this function cannot disable the restart of tasklets as
+ * it cannot wait if called from interrupt context, however the
+ * tasklets will have no effect since the doorbells are disabled. The
+ * driver will call tg3_sge_stop() later from process context, at
+ * which time the tasklets will be stopped if they are still running.
*/
-void t3_sge_stop(struct adapter *adap)
+void t3_sge_stop_dma(struct adapter *adap)
{
t3_set_reg_field(adap, A_SG_CONTROL, F_GLOBALENABLE, 0);
- if (!in_interrupt()) {
- int i;
+}
+
+/**
+ * t3_sge_stop - disable SGE operation completly
+ * @adap: the adapter
+ *
+ * Called from process context. Disables the DMA engine and any
+ * pending queue restart tasklets.
+ */
+void t3_sge_stop(struct adapter *adap)
+{
+ int i;
+
+ t3_sge_stop_dma(adap);

- for (i = 0; i < SGE_QSETS; ++i) {
- struct sge_qset *qs = &adap->sge.qs[i];
+ for (i = 0; i < SGE_QSETS; ++i) {
+ struct sge_qset *qs = &adap->sge.qs[i];

- tasklet_kill(&qs->txq[TXQ_OFLD].qresume_tsk);
- tasklet_kill(&qs->txq[TXQ_CTRL].qresume_tsk);
- }
+ tasklet_kill(&qs->txq[TXQ_OFLD].qresume_tsk);
+ tasklet_kill(&qs->txq[TXQ_CTRL].qresume_tsk);
}
}


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