[PATCH] ath10k: Keep track of which interrupts fired, don't poll them

[PATCH] ath10k: Keep track of which interrupts fired, don't poll them

[Douglas Anderson]

If we have a per CE (Copy Engine) IRQ then we have no summary
register.  Right now the code generates a summary register by
iterating over all copy engines and seeing if they have an interrupt
pending.

This has a problem.  Specifically if _none_ if the Copy Engines have
an interrupt pending then they might go into low power mode and
reading from their address space will cause a full system crash.  This
was seen to happen when two interrupts went off at nearly the same
time.  Both were handled by a single call of ath10k_snoc_napi_poll()
but, because there were two interrupts handled and thus two calls to
napi_schedule() there was still a second call to
ath10k_snoc_napi_poll() which ran with no interrupts pending.

Instead of iterating over all the copy engines, let's just keep track
of the IRQs that fire.  Then we can effectively generate our own
summary without ever needing to read the Copy Engines.

Tested-on: WCN3990 SNOC WLAN.HL.3.2.2-00490-QCAHLSWMTPL-1

Signed-off-by: Douglas Anderson <dianders@chromium.org>
---
This patch continues work to try to squash all instances of the crash
we've been seeing while reading CE registers and hopefully this patch
addresses the true root of the issue.

The first patch that attempted to address these problems landed as
commit 8f9ed93d09a9 ("ath10k: Wait until copy complete is actually
done before completing").  After that Rakesh Pillai posted ("ath10k:
Add interrupt summary based CE processing") [1] and this patch is
based atop that one.  Both of those patches significantly reduced the
instances of problems but didn't fully eliminate them.  Crossing my
fingers that they're all gone now.

[1] https://lore.kernel.org/r/1593193967-29897-1-git-send-email-pillair@codeaurora.org

 drivers/net/wireless/ath/ath10k/ce.c   | 84 ++++++++++----------------
 drivers/net/wireless/ath/ath10k/ce.h   | 14 ++---
 drivers/net/wireless/ath/ath10k/snoc.c | 18 ++++--
 drivers/net/wireless/ath/ath10k/snoc.h |  1 +
 4 files changed, 51 insertions(+), 66 deletions(-)

diff --git a/drivers/net/wireless/ath/ath10k/ce.c b/drivers/net/wireless/ath/ath10k/ce.c
index 1e16f263854a..84ec80c6d08f 100644
--- a/drivers/net/wireless/ath/ath10k/ce.c
+++ b/drivers/net/wireless/ath/ath10k/ce.c
@@ -481,38 +481,6 @@ static inline void ath10k_ce_engine_int_status_clear(struct ath10k *ar,
 	ath10k_ce_write32(ar, ce_ctrl_addr + wm_regs->addr, mask);
 }
 
-static bool ath10k_ce_engine_int_status_check(struct ath10k *ar, u32 ce_ctrl_addr,
-					      unsigned int mask)
-{
-	struct ath10k_hw_ce_host_wm_regs *wm_regs = ar->hw_ce_regs->wm_regs;
-
-	return ath10k_ce_read32(ar, ce_ctrl_addr + wm_regs->addr) & mask;
-}
-
-u32 ath10k_ce_gen_interrupt_summary(struct ath10k *ar)
-{
-	struct ath10k_hw_ce_host_wm_regs *wm_regs = ar->hw_ce_regs->wm_regs;
-	struct ath10k_ce_pipe *ce_state;
-	struct ath10k_ce *ce;
-	u32 irq_summary = 0;
-	u32 ctrl_addr;
-	u32 ce_id;
-
-	ce = ath10k_ce_priv(ar);
-
-	for (ce_id = 0; ce_id < CE_COUNT; ce_id++) {
-		ce_state = &ce->ce_states[ce_id];
-		ctrl_addr = ce_state->ctrl_addr;
-		if (ath10k_ce_engine_int_status_check(ar, ctrl_addr,
-						      wm_regs->cc_mask)) {
-			irq_summary |= BIT(ce_id);
-		}
-	}
-
-	return irq_summary;
-}
-EXPORT_SYMBOL(ath10k_ce_gen_interrupt_summary);
-
 /*
  * Guts of ath10k_ce_send.
  * The caller takes responsibility for any needed locking.
@@ -1399,45 +1367,55 @@ static void ath10k_ce_per_engine_handler_adjust(struct ath10k_ce_pipe *ce_state)
 	ath10k_ce_watermark_intr_disable(ar, ctrl_addr);
 }
 
-int ath10k_ce_disable_interrupts(struct ath10k *ar)
+void ath10k_ce_disable_interrupt(struct ath10k *ar, int ce_id)
 {
 	struct ath10k_ce *ce = ath10k_ce_priv(ar);
 	struct ath10k_ce_pipe *ce_state;
 	u32 ctrl_addr;
-	int ce_id;
 
-	for (ce_id = 0; ce_id < CE_COUNT; ce_id++) {
-		ce_state  = &ce->ce_states[ce_id];
-		if (ce_state->attr_flags & CE_ATTR_POLL)
-			continue;
+	ce_state  = &ce->ce_states[ce_id];
+	if (ce_state->attr_flags & CE_ATTR_POLL)
+		return;
 
-		ctrl_addr = ath10k_ce_base_address(ar, ce_id);
+	ctrl_addr = ath10k_ce_base_address(ar, ce_id);
 
-		ath10k_ce_copy_complete_intr_disable(ar, ctrl_addr);
-		ath10k_ce_error_intr_disable(ar, ctrl_addr);
-		ath10k_ce_watermark_intr_disable(ar, ctrl_addr);
-	}
+	ath10k_ce_copy_complete_intr_disable(ar, ctrl_addr);
+	ath10k_ce_error_intr_disable(ar, ctrl_addr);
+	ath10k_ce_watermark_intr_disable(ar, ctrl_addr);
+}
+EXPORT_SYMBOL(ath10k_ce_disable_interrupt);
 
-	return 0;
+void ath10k_ce_disable_interrupts(struct ath10k *ar)
+{
+	int ce_id;
+
+	for (ce_id = 0; ce_id < CE_COUNT; ce_id++)
+		ath10k_ce_disable_interrupt(ar, ce_id);
 }
 EXPORT_SYMBOL(ath10k_ce_disable_interrupts);
 
-void ath10k_ce_enable_interrupts(struct ath10k *ar)
+void ath10k_ce_enable_interrupt(struct ath10k *ar, int ce_id)
 {
 	struct ath10k_ce *ce = ath10k_ce_priv(ar);
-	int ce_id;
 	struct ath10k_ce_pipe *ce_state;
 
+	ce_state  = &ce->ce_states[ce_id];
+	if (ce_state->attr_flags & CE_ATTR_POLL)
+		return;
+
+	ath10k_ce_per_engine_handler_adjust(ce_state);
+}
+EXPORT_SYMBOL(ath10k_ce_enable_interrupt);
+
+void ath10k_ce_enable_interrupts(struct ath10k *ar)
+{
+	int ce_id;
+
 	/* Enable interrupts for copy engine that
 	 * are not using polling mode.
 	 */
-	for (ce_id = 0; ce_id < CE_COUNT; ce_id++) {
-		ce_state  = &ce->ce_states[ce_id];
-		if (ce_state->attr_flags & CE_ATTR_POLL)
-			continue;
-
-		ath10k_ce_per_engine_handler_adjust(ce_state);
-	}
+	for (ce_id = 0; ce_id < CE_COUNT; ce_id++)
+		ath10k_ce_enable_interrupt(ar, ce_id);
 }
 EXPORT_SYMBOL(ath10k_ce_enable_interrupts);
 
diff --git a/drivers/net/wireless/ath/ath10k/ce.h b/drivers/net/wireless/ath/ath10k/ce.h
index a440aaf74aa4..666ce384a1d8 100644
--- a/drivers/net/wireless/ath/ath10k/ce.h
+++ b/drivers/net/wireless/ath/ath10k/ce.h
@@ -255,12 +255,13 @@ int ath10k_ce_cancel_send_next(struct ath10k_ce_pipe *ce_state,
 /*==================CE Interrupt Handlers====================*/
 void ath10k_ce_per_engine_service_any(struct ath10k *ar);
 void ath10k_ce_per_engine_service(struct ath10k *ar, unsigned int ce_id);
-int ath10k_ce_disable_interrupts(struct ath10k *ar);
+void ath10k_ce_disable_interrupt(struct ath10k *ar, int ce_id);
+void ath10k_ce_disable_interrupts(struct ath10k *ar);
+void ath10k_ce_enable_interrupt(struct ath10k *ar, int ce_id);
 void ath10k_ce_enable_interrupts(struct ath10k *ar);
 void ath10k_ce_dump_registers(struct ath10k *ar,
 			      struct ath10k_fw_crash_data *crash_data);
 
-u32 ath10k_ce_gen_interrupt_summary(struct ath10k *ar);
 void ath10k_ce_alloc_rri(struct ath10k *ar);
 void ath10k_ce_free_rri(struct ath10k *ar);
 
@@ -376,12 +377,9 @@ static inline u32 ath10k_ce_interrupt_summary(struct ath10k *ar)
 {
 	struct ath10k_ce *ce = ath10k_ce_priv(ar);
 
-	if (!ar->hw_params.per_ce_irq)
-		return CE_WRAPPER_INTERRUPT_SUMMARY_HOST_MSI_GET(
-			ce->bus_ops->read32((ar), CE_WRAPPER_BASE_ADDRESS +
-			CE_WRAPPER_INTERRUPT_SUMMARY_ADDRESS));
-	else
-		return ath10k_ce_gen_interrupt_summary(ar);
+	return CE_WRAPPER_INTERRUPT_SUMMARY_HOST_MSI_GET(
+		ce->bus_ops->read32((ar), CE_WRAPPER_BASE_ADDRESS +
+		CE_WRAPPER_INTERRUPT_SUMMARY_ADDRESS));
 }
 
 /* Host software's Copy Engine configuration. */
diff --git a/drivers/net/wireless/ath/ath10k/snoc.c b/drivers/net/wireless/ath/ath10k/snoc.c
index 354d49b1cd45..2fc4dcbab70a 100644
--- a/drivers/net/wireless/ath/ath10k/snoc.c
+++ b/drivers/net/wireless/ath/ath10k/snoc.c
@@ -3,6 +3,7 @@
  * Copyright (c) 2018 The Linux Foundation. All rights reserved.
  */
 
+#include <linux/bits.h>
 #include <linux/clk.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
@@ -1158,7 +1159,9 @@ static irqreturn_t ath10k_snoc_per_engine_handler(int irq, void *arg)
 		return IRQ_HANDLED;
 	}
 
-	ath10k_snoc_irq_disable(ar);
+	ath10k_ce_disable_interrupt(ar, ce_id);
+	set_bit(ce_id, ar_snoc->pending_ce_irqs);
+
 	napi_schedule(&ar->napi);
 
 	return IRQ_HANDLED;
@@ -1167,20 +1170,25 @@ static irqreturn_t ath10k_snoc_per_engine_handler(int irq, void *arg)
 static int ath10k_snoc_napi_poll(struct napi_struct *ctx, int budget)
 {
 	struct ath10k *ar = container_of(ctx, struct ath10k, napi);
+	struct ath10k_snoc *ar_snoc = ath10k_snoc_priv(ar);
 	int done = 0;
+	int ce_id;
 
 	if (test_bit(ATH10K_FLAG_CRASH_FLUSH, &ar->dev_flags)) {
 		napi_complete(ctx);
 		return done;
 	}
 
-	ath10k_ce_per_engine_service_any(ar);
+	for (ce_id = 0; ce_id < CE_COUNT; ce_id++)
+		if (test_and_clear_bit(ce_id, ar_snoc->pending_ce_irqs)) {
+			ath10k_ce_per_engine_service(ar, ce_id);
+			ath10k_ce_enable_interrupt(ar, ce_id);
+		}
+
 	done = ath10k_htt_txrx_compl_task(ar, budget);
 
-	if (done < budget) {
+	if (done < budget)
 		napi_complete(ctx);
-		ath10k_snoc_irq_enable(ar);
-	}
 
 	return done;
 }
diff --git a/drivers/net/wireless/ath/ath10k/snoc.h b/drivers/net/wireless/ath/ath10k/snoc.h
index a3dd06f6ac62..5095d1893681 100644
--- a/drivers/net/wireless/ath/ath10k/snoc.h
+++ b/drivers/net/wireless/ath/ath10k/snoc.h
@@ -78,6 +78,7 @@ struct ath10k_snoc {
 	unsigned long flags;
 	bool xo_cal_supported;
 	u32 xo_cal_data;
+	DECLARE_BITMAP(pending_ce_irqs, CE_COUNT_MAX);
 };
 
 static inline struct ath10k_snoc *ath10k_snoc_priv(struct ath10k *ar)
-- 
2.27.0.383.g050319c2ae-goog

RE: [PATCH] ath10k: Keep track of which interrupts fired, don't poll them

[Rakesh Pillai]

> -----Original Message-----
> From: Douglas Anderson <dianders@chromium.org>
> Sent: Tuesday, July 7, 2020 10:48 PM
> To: kvalo@codeaurora.org; ath10k@lists.infradead.org
> Cc: saiprakash.ranjan@codeaurora.org; linux-arm-msm@vger.kernel.org;
> linux-wireless@vger.kernel.org; pillair@codeaurora.org;
> kuabhs@google.com; Douglas Anderson <dianders@chromium.org>; David
> S. Miller <davem@davemloft.net>; Jakub Kicinski <kuba@kernel.org>; linux-
> kernel@vger.kernel.org; netdev@vger.kernel.org
> Subject: [PATCH] ath10k: Keep track of which interrupts fired, don't poll
> them
> 
> If we have a per CE (Copy Engine) IRQ then we have no summary
> register.  Right now the code generates a summary register by
> iterating over all copy engines and seeing if they have an interrupt
> pending.
> 
> This has a problem.  Specifically if _none_ if the Copy Engines have
> an interrupt pending then they might go into low power mode and
> reading from their address space will cause a full system crash.  This
> was seen to happen when two interrupts went off at nearly the same
> time.  Both were handled by a single call of ath10k_snoc_napi_poll()
> but, because there were two interrupts handled and thus two calls to
> napi_schedule() there was still a second call to
> ath10k_snoc_napi_poll() which ran with no interrupts pending.
> 
> Instead of iterating over all the copy engines, let's just keep track
> of the IRQs that fire.  Then we can effectively generate our own
> summary without ever needing to read the Copy Engines.
> 
> Tested-on: WCN3990 SNOC WLAN.HL.3.2.2-00490-QCAHLSWMTPL-1
> 
> Signed-off-by: Douglas Anderson <dianders@chromium.org>


Reviewed-by:  Rakesh Pillai <pillair@codeaurora.org> 


> ---
> This patch continues work to try to squash all instances of the crash
> we've been seeing while reading CE registers and hopefully this patch
> addresses the true root of the issue.
> 
> The first patch that attempted to address these problems landed as
> commit 8f9ed93d09a9 ("ath10k: Wait until copy complete is actually
> done before completing").  After that Rakesh Pillai posted ("ath10k:
> Add interrupt summary based CE processing") [1] and this patch is
> based atop that one.  Both of those patches significantly reduced the
> instances of problems but didn't fully eliminate them.  Crossing my
> fingers that they're all gone now.
> 
> [1] https://lore.kernel.org/r/1593193967-29897-1-git-send-email-
> pillair@codeaurora.org
> 
>  drivers/net/wireless/ath/ath10k/ce.c   | 84 ++++++++++----------------
>  drivers/net/wireless/ath/ath10k/ce.h   | 14 ++---
>  drivers/net/wireless/ath/ath10k/snoc.c | 18 ++++--
>  drivers/net/wireless/ath/ath10k/snoc.h |  1 +
>  4 files changed, 51 insertions(+), 66 deletions(-)
> 
> diff --git a/drivers/net/wireless/ath/ath10k/ce.c
> b/drivers/net/wireless/ath/ath10k/ce.c
> index 1e16f263854a..84ec80c6d08f 100644
> --- a/drivers/net/wireless/ath/ath10k/ce.c
> +++ b/drivers/net/wireless/ath/ath10k/ce.c
> @@ -481,38 +481,6 @@ static inline void
> ath10k_ce_engine_int_status_clear(struct ath10k *ar,
>  	ath10k_ce_write32(ar, ce_ctrl_addr + wm_regs->addr, mask);
>  }
> 
> -static bool ath10k_ce_engine_int_status_check(struct ath10k *ar, u32
> ce_ctrl_addr,
> -					      unsigned int mask)
> -{
> -	struct ath10k_hw_ce_host_wm_regs *wm_regs = ar->hw_ce_regs-
> >wm_regs;
> -
> -	return ath10k_ce_read32(ar, ce_ctrl_addr + wm_regs->addr) &
> mask;
> -}
> -
> -u32 ath10k_ce_gen_interrupt_summary(struct ath10k *ar)
> -{
> -	struct ath10k_hw_ce_host_wm_regs *wm_regs = ar->hw_ce_regs-
> >wm_regs;
> -	struct ath10k_ce_pipe *ce_state;
> -	struct ath10k_ce *ce;
> -	u32 irq_summary = 0;
> -	u32 ctrl_addr;
> -	u32 ce_id;
> -
> -	ce = ath10k_ce_priv(ar);
> -
> -	for (ce_id = 0; ce_id < CE_COUNT; ce_id++) {
> -		ce_state = &ce->ce_states[ce_id];
> -		ctrl_addr = ce_state->ctrl_addr;
> -		if (ath10k_ce_engine_int_status_check(ar, ctrl_addr,
> -						      wm_regs->cc_mask)) {
> -			irq_summary |= BIT(ce_id);
> -		}
> -	}
> -
> -	return irq_summary;
> -}
> -EXPORT_SYMBOL(ath10k_ce_gen_interrupt_summary);
> -
>  /*
>   * Guts of ath10k_ce_send.
>   * The caller takes responsibility for any needed locking.
> @@ -1399,45 +1367,55 @@ static void
> ath10k_ce_per_engine_handler_adjust(struct ath10k_ce_pipe *ce_state)
>  	ath10k_ce_watermark_intr_disable(ar, ctrl_addr);
>  }
> 
> -int ath10k_ce_disable_interrupts(struct ath10k *ar)
> +void ath10k_ce_disable_interrupt(struct ath10k *ar, int ce_id)
>  {
>  	struct ath10k_ce *ce = ath10k_ce_priv(ar);
>  	struct ath10k_ce_pipe *ce_state;
>  	u32 ctrl_addr;
> -	int ce_id;
> 
> -	for (ce_id = 0; ce_id < CE_COUNT; ce_id++) {
> -		ce_state  = &ce->ce_states[ce_id];
> -		if (ce_state->attr_flags & CE_ATTR_POLL)
> -			continue;
> +	ce_state  = &ce->ce_states[ce_id];
> +	if (ce_state->attr_flags & CE_ATTR_POLL)
> +		return;
> 
> -		ctrl_addr = ath10k_ce_base_address(ar, ce_id);
> +	ctrl_addr = ath10k_ce_base_address(ar, ce_id);
> 
> -		ath10k_ce_copy_complete_intr_disable(ar, ctrl_addr);
> -		ath10k_ce_error_intr_disable(ar, ctrl_addr);
> -		ath10k_ce_watermark_intr_disable(ar, ctrl_addr);
> -	}
> +	ath10k_ce_copy_complete_intr_disable(ar, ctrl_addr);
> +	ath10k_ce_error_intr_disable(ar, ctrl_addr);
> +	ath10k_ce_watermark_intr_disable(ar, ctrl_addr);
> +}
> +EXPORT_SYMBOL(ath10k_ce_disable_interrupt);
> 
> -	return 0;
> +void ath10k_ce_disable_interrupts(struct ath10k *ar)
> +{
> +	int ce_id;
> +
> +	for (ce_id = 0; ce_id < CE_COUNT; ce_id++)
> +		ath10k_ce_disable_interrupt(ar, ce_id);
>  }
>  EXPORT_SYMBOL(ath10k_ce_disable_interrupts);
> 
> -void ath10k_ce_enable_interrupts(struct ath10k *ar)
> +void ath10k_ce_enable_interrupt(struct ath10k *ar, int ce_id)
>  {
>  	struct ath10k_ce *ce = ath10k_ce_priv(ar);
> -	int ce_id;
>  	struct ath10k_ce_pipe *ce_state;
> 
> +	ce_state  = &ce->ce_states[ce_id];
> +	if (ce_state->attr_flags & CE_ATTR_POLL)
> +		return;
> +
> +	ath10k_ce_per_engine_handler_adjust(ce_state);
> +}
> +EXPORT_SYMBOL(ath10k_ce_enable_interrupt);
> +
> +void ath10k_ce_enable_interrupts(struct ath10k *ar)
> +{
> +	int ce_id;
> +
>  	/* Enable interrupts for copy engine that
>  	 * are not using polling mode.
>  	 */
> -	for (ce_id = 0; ce_id < CE_COUNT; ce_id++) {
> -		ce_state  = &ce->ce_states[ce_id];
> -		if (ce_state->attr_flags & CE_ATTR_POLL)
> -			continue;
> -
> -		ath10k_ce_per_engine_handler_adjust(ce_state);
> -	}
> +	for (ce_id = 0; ce_id < CE_COUNT; ce_id++)
> +		ath10k_ce_enable_interrupt(ar, ce_id);
>  }
>  EXPORT_SYMBOL(ath10k_ce_enable_interrupts);
> 
> diff --git a/drivers/net/wireless/ath/ath10k/ce.h
> b/drivers/net/wireless/ath/ath10k/ce.h
> index a440aaf74aa4..666ce384a1d8 100644
> --- a/drivers/net/wireless/ath/ath10k/ce.h
> +++ b/drivers/net/wireless/ath/ath10k/ce.h
> @@ -255,12 +255,13 @@ int ath10k_ce_cancel_send_next(struct
> ath10k_ce_pipe *ce_state,
>  /*==================CE Interrupt Handlers====================*/
>  void ath10k_ce_per_engine_service_any(struct ath10k *ar);
>  void ath10k_ce_per_engine_service(struct ath10k *ar, unsigned int ce_id);
> -int ath10k_ce_disable_interrupts(struct ath10k *ar);
> +void ath10k_ce_disable_interrupt(struct ath10k *ar, int ce_id);
> +void ath10k_ce_disable_interrupts(struct ath10k *ar);
> +void ath10k_ce_enable_interrupt(struct ath10k *ar, int ce_id);
>  void ath10k_ce_enable_interrupts(struct ath10k *ar);
>  void ath10k_ce_dump_registers(struct ath10k *ar,
>  			      struct ath10k_fw_crash_data *crash_data);
> 
> -u32 ath10k_ce_gen_interrupt_summary(struct ath10k *ar);
>  void ath10k_ce_alloc_rri(struct ath10k *ar);
>  void ath10k_ce_free_rri(struct ath10k *ar);
> 
> @@ -376,12 +377,9 @@ static inline u32
> ath10k_ce_interrupt_summary(struct ath10k *ar)
>  {
>  	struct ath10k_ce *ce = ath10k_ce_priv(ar);
> 
> -	if (!ar->hw_params.per_ce_irq)
> -		return
> CE_WRAPPER_INTERRUPT_SUMMARY_HOST_MSI_GET(
> -			ce->bus_ops->read32((ar),
> CE_WRAPPER_BASE_ADDRESS +
> -			CE_WRAPPER_INTERRUPT_SUMMARY_ADDRESS));
> -	else
> -		return ath10k_ce_gen_interrupt_summary(ar);
> +	return CE_WRAPPER_INTERRUPT_SUMMARY_HOST_MSI_GET(
> +		ce->bus_ops->read32((ar), CE_WRAPPER_BASE_ADDRESS +
> +		CE_WRAPPER_INTERRUPT_SUMMARY_ADDRESS));
>  }
> 
>  /* Host software's Copy Engine configuration. */
> diff --git a/drivers/net/wireless/ath/ath10k/snoc.c
> b/drivers/net/wireless/ath/ath10k/snoc.c
> index 354d49b1cd45..2fc4dcbab70a 100644
> --- a/drivers/net/wireless/ath/ath10k/snoc.c
> +++ b/drivers/net/wireless/ath/ath10k/snoc.c
> @@ -3,6 +3,7 @@
>   * Copyright (c) 2018 The Linux Foundation. All rights reserved.
>   */
> 
> +#include <linux/bits.h>
>  #include <linux/clk.h>
>  #include <linux/kernel.h>
>  #include <linux/module.h>
> @@ -1158,7 +1159,9 @@ static irqreturn_t
> ath10k_snoc_per_engine_handler(int irq, void *arg)
>  		return IRQ_HANDLED;
>  	}
> 
> -	ath10k_snoc_irq_disable(ar);
> +	ath10k_ce_disable_interrupt(ar, ce_id);
> +	set_bit(ce_id, ar_snoc->pending_ce_irqs);
> +
>  	napi_schedule(&ar->napi);
> 
>  	return IRQ_HANDLED;
> @@ -1167,20 +1170,25 @@ static irqreturn_t
> ath10k_snoc_per_engine_handler(int irq, void *arg)
>  static int ath10k_snoc_napi_poll(struct napi_struct *ctx, int budget)
>  {
>  	struct ath10k *ar = container_of(ctx, struct ath10k, napi);
> +	struct ath10k_snoc *ar_snoc = ath10k_snoc_priv(ar);
>  	int done = 0;
> +	int ce_id;
> 
>  	if (test_bit(ATH10K_FLAG_CRASH_FLUSH, &ar->dev_flags)) {
>  		napi_complete(ctx);
>  		return done;
>  	}
> 
> -	ath10k_ce_per_engine_service_any(ar);
> +	for (ce_id = 0; ce_id < CE_COUNT; ce_id++)
> +		if (test_and_clear_bit(ce_id, ar_snoc->pending_ce_irqs)) {
> +			ath10k_ce_per_engine_service(ar, ce_id);
> +			ath10k_ce_enable_interrupt(ar, ce_id);
> +		}
> +
>  	done = ath10k_htt_txrx_compl_task(ar, budget);
> 
> -	if (done < budget) {
> +	if (done < budget)
>  		napi_complete(ctx);
> -		ath10k_snoc_irq_enable(ar);
> -	}
> 
>  	return done;
>  }
> diff --git a/drivers/net/wireless/ath/ath10k/snoc.h
> b/drivers/net/wireless/ath/ath10k/snoc.h
> index a3dd06f6ac62..5095d1893681 100644
> --- a/drivers/net/wireless/ath/ath10k/snoc.h
> +++ b/drivers/net/wireless/ath/ath10k/snoc.h
> @@ -78,6 +78,7 @@ struct ath10k_snoc {
>  	unsigned long flags;
>  	bool xo_cal_supported;
>  	u32 xo_cal_data;
> +	DECLARE_BITMAP(pending_ce_irqs, CE_COUNT_MAX);
>  };
> 
>  static inline struct ath10k_snoc *ath10k_snoc_priv(struct ath10k *ar)
> --
> 2.27.0.383.g050319c2ae-goog

Re: [PATCH] ath10k: Keep track of which interrupts fired, don't poll them

[Brian Norris]

On Tue, Jul 7, 2020 at 10:18 AM Douglas Anderson <dianders@chromium.org> wrote:
> diff --git a/drivers/net/wireless/ath/ath10k/ce.h b/drivers/net/wireless/ath/ath10k/ce.h
> index a440aaf74aa4..666ce384a1d8 100644
> --- a/drivers/net/wireless/ath/ath10k/ce.h
> +++ b/drivers/net/wireless/ath/ath10k/ce.h
...
> @@ -376,12 +377,9 @@ static inline u32 ath10k_ce_interrupt_summary(struct ath10k *ar)
>  {
>         struct ath10k_ce *ce = ath10k_ce_priv(ar);
>
> -       if (!ar->hw_params.per_ce_irq)

If I'm reading correctly, you're removing the only remaining use of
'per_ce_irq'. Should we kill the field entirely? Or perhaps we should
leave some kind of WARN_ON() (BUG_ON()?) if this function is called
erroneously with per_ce_irq==true? But I suppose this driver is full
of landmines if the CE API is used incorrectly.

> -               return CE_WRAPPER_INTERRUPT_SUMMARY_HOST_MSI_GET(
> -                       ce->bus_ops->read32((ar), CE_WRAPPER_BASE_ADDRESS +
> -                       CE_WRAPPER_INTERRUPT_SUMMARY_ADDRESS));
> -       else
> -               return ath10k_ce_gen_interrupt_summary(ar);
> +       return CE_WRAPPER_INTERRUPT_SUMMARY_HOST_MSI_GET(
> +               ce->bus_ops->read32((ar), CE_WRAPPER_BASE_ADDRESS +
> +               CE_WRAPPER_INTERRUPT_SUMMARY_ADDRESS));
>  }
>
>  /* Host software's Copy Engine configuration. */

> diff --git a/drivers/net/wireless/ath/ath10k/snoc.h b/drivers/net/wireless/ath/ath10k/snoc.h
> index a3dd06f6ac62..5095d1893681 100644
> --- a/drivers/net/wireless/ath/ath10k/snoc.h
> +++ b/drivers/net/wireless/ath/ath10k/snoc.h
> @@ -78,6 +78,7 @@ struct ath10k_snoc {
>         unsigned long flags;
>         bool xo_cal_supported;
>         u32 xo_cal_data;
> +       DECLARE_BITMAP(pending_ce_irqs, CE_COUNT_MAX);

Do you need to clear this map if the interface goes down or if there's
a firmware crash? Right now, I don't think there's a guarantee that
we'll run through a NAPI poll in those cases, which is the only place
you clear the map, and if the hardware/firmware has been reset, the
state map is probably not valid.

Otherwise, looks OK to me:

Reviewed-by: Brian Norris <briannorris@chromium.org>

Re: [PATCH] ath10k: Keep track of which interrupts fired, don't poll them

[Doug Anderson]

Hi,

On Wed, Jul 8, 2020 at 4:03 PM Brian Norris <briannorris@chromium.org> wrote:
>
> On Tue, Jul 7, 2020 at 10:18 AM Douglas Anderson <dianders@chromium.org> wrote:
> > diff --git a/drivers/net/wireless/ath/ath10k/ce.h b/drivers/net/wireless/ath/ath10k/ce.h
> > index a440aaf74aa4..666ce384a1d8 100644
> > --- a/drivers/net/wireless/ath/ath10k/ce.h
> > +++ b/drivers/net/wireless/ath/ath10k/ce.h
> ...
> > @@ -376,12 +377,9 @@ static inline u32 ath10k_ce_interrupt_summary(struct ath10k *ar)
> >  {
> >         struct ath10k_ce *ce = ath10k_ce_priv(ar);
> >
> > -       if (!ar->hw_params.per_ce_irq)
>
> If I'm reading correctly, you're removing the only remaining use of
> 'per_ce_irq'. Should we kill the field entirely?

Ah, you are indeed correct!  I hadn't noticed that.  Unless I hear
otherwise, I'll send a v2 tomorrow that removes the field entirely.


> Or perhaps we should
> leave some kind of WARN_ON() (BUG_ON()?) if this function is called
> erroneously with per_ce_irq==true? But I suppose this driver is full
> of landmines if the CE API is used incorrectly.

Yeah, I originally had a WARN_ON() here and then took it out because
it seemed like extra overhead and, as you said, someone writing the
code has to know how the API works already I think.  ...but I'll add
it back in if people want.


> > -               return CE_WRAPPER_INTERRUPT_SUMMARY_HOST_MSI_GET(
> > -                       ce->bus_ops->read32((ar), CE_WRAPPER_BASE_ADDRESS +
> > -                       CE_WRAPPER_INTERRUPT_SUMMARY_ADDRESS));
> > -       else
> > -               return ath10k_ce_gen_interrupt_summary(ar);
> > +       return CE_WRAPPER_INTERRUPT_SUMMARY_HOST_MSI_GET(
> > +               ce->bus_ops->read32((ar), CE_WRAPPER_BASE_ADDRESS +
> > +               CE_WRAPPER_INTERRUPT_SUMMARY_ADDRESS));
> >  }
> >
> >  /* Host software's Copy Engine configuration. */
>
> > diff --git a/drivers/net/wireless/ath/ath10k/snoc.h b/drivers/net/wireless/ath/ath10k/snoc.h
> > index a3dd06f6ac62..5095d1893681 100644
> > --- a/drivers/net/wireless/ath/ath10k/snoc.h
> > +++ b/drivers/net/wireless/ath/ath10k/snoc.h
> > @@ -78,6 +78,7 @@ struct ath10k_snoc {
> >         unsigned long flags;
> >         bool xo_cal_supported;
> >         u32 xo_cal_data;
> > +       DECLARE_BITMAP(pending_ce_irqs, CE_COUNT_MAX);
>
> Do you need to clear this map if the interface goes down or if there's
> a firmware crash? Right now, I don't think there's a guarantee that
> we'll run through a NAPI poll in those cases, which is the only place
> you clear the map, and if the hardware/firmware has been reset, the
> state map is probably not valid.

Seems like a good idea.  Is the right place at the start of
ath10k_snoc_hif_start()?


> Otherwise, looks OK to me:
>
> Reviewed-by: Brian Norris <briannorris@chromium.org>

Thanks for the review!

-Doug

Re: [PATCH] ath10k: Keep track of which interrupts fired, don't poll them

[Brian Norris]

On Wed, Jul 8, 2020 at 4:14 PM Doug Anderson <dianders@chromium.org> wrote:
> On Wed, Jul 8, 2020 at 4:03 PM Brian Norris <briannorris@chromium.org> wrote:
> > If I'm reading correctly, you're removing the only remaining use of
> > 'per_ce_irq'. Should we kill the field entirely?
>
> Ah, you are indeed correct!  I hadn't noticed that.  Unless I hear
> otherwise, I'll send a v2 tomorrow that removes the field entirely.

A healthy middle ground might put that in a patch 2, so it's easily
dropped if desired. *shrug*

> > Or perhaps we should
> > leave some kind of WARN_ON() (BUG_ON()?) if this function is called
> > erroneously with per_ce_irq==true? But I suppose this driver is full
> > of landmines if the CE API is used incorrectly.
>
> Yeah, I originally had a WARN_ON() here and then took it out because
> it seemed like extra overhead and, as you said, someone writing the
> code has to know how the API works already I think.  ...but I'll add
> it back in if people want.

I believe WARN_ON() and friends have a built-in unlikely(), so it
shouldn't have much overhead. But I don't really mind either way.

> > Do you need to clear this map if the interface goes down or if there's
> > a firmware crash? Right now, I don't think there's a guarantee that
> > we'll run through a NAPI poll in those cases, which is the only place
> > you clear the map, and if the hardware/firmware has been reset, the
> > state map is probably not valid.
>
> Seems like a good idea.  Is the right place at the start of
> ath10k_snoc_hif_start()?

Either there or in .power_down()/.power_up(). I think either would be
equally correct, but I'm not entirely sure if the semantic difference
is meaningful for this.

Brian

Re: [PATCH] ath10k: Keep track of which interrupts fired, don't poll them

[Doug Anderson]

Hi,

On Wed, Jul 8, 2020 at 4:40 PM Brian Norris <briannorris@chromium.org> wrote:
>
> On Wed, Jul 8, 2020 at 4:14 PM Doug Anderson <dianders@chromium.org> wrote:
> > On Wed, Jul 8, 2020 at 4:03 PM Brian Norris <briannorris@chromium.org> wrote:
> > > If I'm reading correctly, you're removing the only remaining use of
> > > 'per_ce_irq'. Should we kill the field entirely?
> >
> > Ah, you are indeed correct!  I hadn't noticed that.  Unless I hear
> > otherwise, I'll send a v2 tomorrow that removes the field entirely.
>
> A healthy middle ground might put that in a patch 2, so it's easily
> dropped if desired. *shrug*

Sure, sounds like a plan.


> > > Or perhaps we should
> > > leave some kind of WARN_ON() (BUG_ON()?) if this function is called
> > > erroneously with per_ce_irq==true? But I suppose this driver is full
> > > of landmines if the CE API is used incorrectly.
> >
> > Yeah, I originally had a WARN_ON() here and then took it out because
> > it seemed like extra overhead and, as you said, someone writing the
> > code has to know how the API works already I think.  ...but I'll add
> > it back in if people want.
>
> I believe WARN_ON() and friends have a built-in unlikely(), so it
> shouldn't have much overhead. But I don't really mind either way.

Since you don't feel strongly, leaving it off.


> > > Do you need to clear this map if the interface goes down or if there's
> > > a firmware crash? Right now, I don't think there's a guarantee that
> > > we'll run through a NAPI poll in those cases, which is the only place
> > > you clear the map, and if the hardware/firmware has been reset, the
> > > state map is probably not valid.
> >
> > Seems like a good idea.  Is the right place at the start of
> > ath10k_snoc_hif_start()?
>
> Either there or in .power_down()/.power_up(). I think either would be
> equally correct, but I'm not entirely sure if the semantic difference
> is meaningful for this.

Will choose ath10k_snoc_hif_start() since it's where napi_enable() is
and ath10k_snoc_irq_enable() are and those are related.


-Doug