* [PATCH 1/3] dmaengine: at_xdmac: remove BUG_ON macro in tasklet
@ 2019-02-05 11:03 Nicolas Ferre
2019-02-05 11:03 ` [PATCH 2/3] dmaengine: at_xdmac: enhance channel errors handling " Nicolas Ferre
` (2 more replies)
0 siblings, 3 replies; 8+ messages in thread
From: Nicolas Ferre @ 2019-02-05 11:03 UTC (permalink / raw)
To: Ludovic Desroches, linux-arm-kernel, dmaengine, Vinod Koul
Cc: Alexandre Belloni, linux-kernel
Even if this case shouldn't happen when controller is properly programmed,
it's still better to avoid dumping a kernel Oops for this.
As the sequence may happen only for debugging purposes, log the error and
just finish the tasklet call.
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
---
drivers/dma/at_xdmac.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index fe69dccfa0c0..37a269420435 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -1606,7 +1606,11 @@ static void at_xdmac_tasklet(unsigned long data)
struct at_xdmac_desc,
xfer_node);
dev_vdbg(chan2dev(&atchan->chan), "%s: desc 0x%p\n", __func__, desc);
- BUG_ON(!desc->active_xfer);
+ if (!desc->active_xfer) {
+ dev_err(chan2dev(&atchan->chan), "Xfer not active: exiting");
+ spin_unlock_bh(&atchan->lock);
+ return;
+ }
txd = &desc->tx_dma_desc;
--
2.17.1
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^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH 2/3] dmaengine: at_xdmac: enhance channel errors handling in tasklet
2019-02-05 11:03 [PATCH 1/3] dmaengine: at_xdmac: remove BUG_ON macro in tasklet Nicolas Ferre
@ 2019-02-05 11:03 ` Nicolas Ferre
2019-02-05 12:33 ` Ludovic Desroches
2019-02-11 11:58 ` Vinod Koul
2019-02-05 11:03 ` [PATCH 3/3] dmaengine: at_xdmac: only monitor overflow errors for peripheral xfer Nicolas Ferre
2019-02-05 12:30 ` [PATCH 1/3] dmaengine: at_xdmac: remove BUG_ON macro in tasklet Ludovic Desroches
2 siblings, 2 replies; 8+ messages in thread
From: Nicolas Ferre @ 2019-02-05 11:03 UTC (permalink / raw)
To: Ludovic Desroches, linux-arm-kernel, dmaengine, Vinod Koul
Cc: Alexandre Belloni, linux-kernel
Complement the identification of errors with stoping the channel and
dumping the descriptor that led to the error case.
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
---
drivers/dma/at_xdmac.c | 43 ++++++++++++++++++++++++++++++++++++------
1 file changed, 37 insertions(+), 6 deletions(-)
diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index 37a269420435..ec7a29d8e448 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -1575,6 +1575,41 @@ static void at_xdmac_handle_cyclic(struct at_xdmac_chan *atchan)
dmaengine_desc_get_callback_invoke(txd, NULL);
}
+static void at_xdmac_handle_error(struct at_xdmac_chan *atchan)
+{
+ struct at_xdmac *atxdmac = to_at_xdmac(atchan->chan.device);
+ struct at_xdmac_desc *bad_desc;
+
+ /*
+ * The descriptor currently at the head of the active list is
+ * broked. Since we don't have any way to report errors, we'll
+ * just have to scream loudly and try to carry on.
+ */
+ if (atchan->irq_status & AT_XDMAC_CIS_RBEIS)
+ dev_err(chan2dev(&atchan->chan), "read bus error!!!");
+ if (atchan->irq_status & AT_XDMAC_CIS_WBEIS)
+ dev_err(chan2dev(&atchan->chan), "write bus error!!!");
+ if (atchan->irq_status & AT_XDMAC_CIS_ROIS)
+ dev_err(chan2dev(&atchan->chan), "request overflow error!!!");
+
+ spin_lock_bh(&atchan->lock);
+ /* Channel must be disabled first as it's not done automatically */
+ at_xdmac_write(atxdmac, AT_XDMAC_GD, atchan->mask);
+ while (at_xdmac_read(atxdmac, AT_XDMAC_GS) & atchan->mask)
+ cpu_relax();
+ bad_desc = list_first_entry(&atchan->xfers_list,
+ struct at_xdmac_desc,
+ xfer_node);
+ spin_unlock_bh(&atchan->lock);
+ /* Print bad descriptor's details if needed */
+ dev_dbg(chan2dev(&atchan->chan),
+ "%s: lld: mbr_sa=%pad, mbr_da=%pad, mbr_ubc=0x%08x\n",
+ __func__, &bad_desc->lld.mbr_sa, &bad_desc->lld.mbr_da,
+ bad_desc->lld.mbr_ubc);
+
+ /* Then continue with usual descriptor management */
+}
+
static void at_xdmac_tasklet(unsigned long data)
{
struct at_xdmac_chan *atchan = (struct at_xdmac_chan *)data;
@@ -1594,12 +1629,8 @@ static void at_xdmac_tasklet(unsigned long data)
|| (atchan->irq_status & error_mask)) {
struct dma_async_tx_descriptor *txd;
- if (atchan->irq_status & AT_XDMAC_CIS_RBEIS)
- dev_err(chan2dev(&atchan->chan), "read bus error!!!");
- if (atchan->irq_status & AT_XDMAC_CIS_WBEIS)
- dev_err(chan2dev(&atchan->chan), "write bus error!!!");
- if (atchan->irq_status & AT_XDMAC_CIS_ROIS)
- dev_err(chan2dev(&atchan->chan), "request overflow error!!!");
+ if (atchan->irq_status & error_mask)
+ at_xdmac_handle_error(atchan);
spin_lock(&atchan->lock);
desc = list_first_entry(&atchan->xfers_list,
--
2.17.1
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^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH 3/3] dmaengine: at_xdmac: only monitor overflow errors for peripheral xfer
2019-02-05 11:03 [PATCH 1/3] dmaengine: at_xdmac: remove BUG_ON macro in tasklet Nicolas Ferre
2019-02-05 11:03 ` [PATCH 2/3] dmaengine: at_xdmac: enhance channel errors handling " Nicolas Ferre
@ 2019-02-05 11:03 ` Nicolas Ferre
2019-02-05 12:35 ` Ludovic Desroches
2019-02-05 12:30 ` [PATCH 1/3] dmaengine: at_xdmac: remove BUG_ON macro in tasklet Ludovic Desroches
2 siblings, 1 reply; 8+ messages in thread
From: Nicolas Ferre @ 2019-02-05 11:03 UTC (permalink / raw)
To: Ludovic Desroches, linux-arm-kernel, dmaengine, Vinod Koul
Cc: Alexandre Belloni, linux-kernel
The overflow error flag (ROI: Request Overflow Error) is only relevant
for the case when the channel handles a peripheral synchronized transfer.
Not in the case of memory to memory transfer where there is no hardware
request signal.
Remove the use of this interrupt source in such a case. It's based on
the first descriptor which holds the configuration for the whole
linked list transfer.
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
---
drivers/dma/at_xdmac.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index ec7a29d8e448..b558a23ffbc2 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -308,6 +308,11 @@ static inline int at_xdmac_csize(u32 maxburst)
return csize;
};
+static inline bool at_xdmac_chan_is_peripheral_xfer(u32 cfg)
+{
+ return cfg & AT_XDMAC_CC_TYPE_PER_TRAN;
+}
+
static inline u8 at_xdmac_get_dwidth(u32 cfg)
{
return (cfg & AT_XDMAC_CC_DWIDTH_MASK) >> AT_XDMAC_CC_DWIDTH_OFFSET;
@@ -389,7 +394,13 @@ static void at_xdmac_start_xfer(struct at_xdmac_chan *atchan,
at_xdmac_chan_read(atchan, AT_XDMAC_CUBC));
at_xdmac_chan_write(atchan, AT_XDMAC_CID, 0xffffffff);
- reg = AT_XDMAC_CIE_RBEIE | AT_XDMAC_CIE_WBEIE | AT_XDMAC_CIE_ROIE;
+ reg = AT_XDMAC_CIE_RBEIE | AT_XDMAC_CIE_WBEIE;
+ /*
+ * Request Overflow Error is only for peripheral synchronized transfers
+ */
+ if (at_xdmac_chan_is_peripheral_xfer(first->lld.mbr_cfg))
+ reg |= AT_XDMAC_CIE_ROIE;
+
/*
* There is no end of list when doing cyclic dma, we need to get
* an interrupt after each periods.
--
2.17.1
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^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH 1/3] dmaengine: at_xdmac: remove BUG_ON macro in tasklet
2019-02-05 11:03 [PATCH 1/3] dmaengine: at_xdmac: remove BUG_ON macro in tasklet Nicolas Ferre
2019-02-05 11:03 ` [PATCH 2/3] dmaengine: at_xdmac: enhance channel errors handling " Nicolas Ferre
2019-02-05 11:03 ` [PATCH 3/3] dmaengine: at_xdmac: only monitor overflow errors for peripheral xfer Nicolas Ferre
@ 2019-02-05 12:30 ` Ludovic Desroches
2 siblings, 0 replies; 8+ messages in thread
From: Ludovic Desroches @ 2019-02-05 12:30 UTC (permalink / raw)
To: Nicolas Ferre
Cc: dmaengine, Vinod Koul, Alexandre Belloni, linux-arm-kernel, linux-kernel
On Tue, Feb 05, 2019 at 12:03:41PM +0100, Nicolas Ferre wrote:
> Even if this case shouldn't happen when controller is properly programmed,
> it's still better to avoid dumping a kernel Oops for this.
> As the sequence may happen only for debugging purposes, log the error and
> just finish the tasklet call.
>
> Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Thanks
> ---
> drivers/dma/at_xdmac.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
> index fe69dccfa0c0..37a269420435 100644
> --- a/drivers/dma/at_xdmac.c
> +++ b/drivers/dma/at_xdmac.c
> @@ -1606,7 +1606,11 @@ static void at_xdmac_tasklet(unsigned long data)
> struct at_xdmac_desc,
> xfer_node);
> dev_vdbg(chan2dev(&atchan->chan), "%s: desc 0x%p\n", __func__, desc);
> - BUG_ON(!desc->active_xfer);
> + if (!desc->active_xfer) {
> + dev_err(chan2dev(&atchan->chan), "Xfer not active: exiting");
> + spin_unlock_bh(&atchan->lock);
> + return;
> + }
>
> txd = &desc->tx_dma_desc;
>
> --
> 2.17.1
>
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^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH 2/3] dmaengine: at_xdmac: enhance channel errors handling in tasklet
2019-02-05 11:03 ` [PATCH 2/3] dmaengine: at_xdmac: enhance channel errors handling " Nicolas Ferre
@ 2019-02-05 12:33 ` Ludovic Desroches
2019-02-11 11:58 ` Vinod Koul
1 sibling, 0 replies; 8+ messages in thread
From: Ludovic Desroches @ 2019-02-05 12:33 UTC (permalink / raw)
To: Nicolas Ferre
Cc: dmaengine, Vinod Koul, Alexandre Belloni, linux-arm-kernel, linux-kernel
On Tue, Feb 05, 2019 at 12:03:42PM +0100, Nicolas Ferre wrote:
> Complement the identification of errors with stoping the channel and
> dumping the descriptor that led to the error case.
>
> Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
> ---
> drivers/dma/at_xdmac.c | 43 ++++++++++++++++++++++++++++++++++++------
> 1 file changed, 37 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
> index 37a269420435..ec7a29d8e448 100644
> --- a/drivers/dma/at_xdmac.c
> +++ b/drivers/dma/at_xdmac.c
> @@ -1575,6 +1575,41 @@ static void at_xdmac_handle_cyclic(struct at_xdmac_chan *atchan)
> dmaengine_desc_get_callback_invoke(txd, NULL);
> }
>
> +static void at_xdmac_handle_error(struct at_xdmac_chan *atchan)
> +{
> + struct at_xdmac *atxdmac = to_at_xdmac(atchan->chan.device);
> + struct at_xdmac_desc *bad_desc;
> +
> + /*
> + * The descriptor currently at the head of the active list is
> + * broked. Since we don't have any way to report errors, we'll
> + * just have to scream loudly and try to carry on.
> + */
> + if (atchan->irq_status & AT_XDMAC_CIS_RBEIS)
> + dev_err(chan2dev(&atchan->chan), "read bus error!!!");
> + if (atchan->irq_status & AT_XDMAC_CIS_WBEIS)
> + dev_err(chan2dev(&atchan->chan), "write bus error!!!");
> + if (atchan->irq_status & AT_XDMAC_CIS_ROIS)
> + dev_err(chan2dev(&atchan->chan), "request overflow error!!!");
> +
> + spin_lock_bh(&atchan->lock);
> + /* Channel must be disabled first as it's not done automatically */
> + at_xdmac_write(atxdmac, AT_XDMAC_GD, atchan->mask);
> + while (at_xdmac_read(atxdmac, AT_XDMAC_GS) & atchan->mask)
> + cpu_relax();
> + bad_desc = list_first_entry(&atchan->xfers_list,
> + struct at_xdmac_desc,
> + xfer_node);
> + spin_unlock_bh(&atchan->lock);
> + /* Print bad descriptor's details if needed */
> + dev_dbg(chan2dev(&atchan->chan),
> + "%s: lld: mbr_sa=%pad, mbr_da=%pad, mbr_ubc=0x%08x\n",
> + __func__, &bad_desc->lld.mbr_sa, &bad_desc->lld.mbr_da,
> + bad_desc->lld.mbr_ubc);
> +
> + /* Then continue with usual descriptor management */
> +}
> +
> static void at_xdmac_tasklet(unsigned long data)
> {
> struct at_xdmac_chan *atchan = (struct at_xdmac_chan *)data;
> @@ -1594,12 +1629,8 @@ static void at_xdmac_tasklet(unsigned long data)
> || (atchan->irq_status & error_mask)) {
> struct dma_async_tx_descriptor *txd;
>
> - if (atchan->irq_status & AT_XDMAC_CIS_RBEIS)
> - dev_err(chan2dev(&atchan->chan), "read bus error!!!");
> - if (atchan->irq_status & AT_XDMAC_CIS_WBEIS)
> - dev_err(chan2dev(&atchan->chan), "write bus error!!!");
> - if (atchan->irq_status & AT_XDMAC_CIS_ROIS)
> - dev_err(chan2dev(&atchan->chan), "request overflow error!!!");
> + if (atchan->irq_status & error_mask)
> + at_xdmac_handle_error(atchan);
>
> spin_lock(&atchan->lock);
> desc = list_first_entry(&atchan->xfers_list,
> --
> 2.17.1
>
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^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH 3/3] dmaengine: at_xdmac: only monitor overflow errors for peripheral xfer
2019-02-05 11:03 ` [PATCH 3/3] dmaengine: at_xdmac: only monitor overflow errors for peripheral xfer Nicolas Ferre
@ 2019-02-05 12:35 ` Ludovic Desroches
0 siblings, 0 replies; 8+ messages in thread
From: Ludovic Desroches @ 2019-02-05 12:35 UTC (permalink / raw)
To: Nicolas Ferre
Cc: dmaengine, Vinod Koul, Alexandre Belloni, linux-arm-kernel, linux-kernel
On Tue, Feb 05, 2019 at 12:03:43PM +0100, Nicolas Ferre wrote:
> The overflow error flag (ROI: Request Overflow Error) is only relevant
> for the case when the channel handles a peripheral synchronized transfer.
> Not in the case of memory to memory transfer where there is no hardware
> request signal.
>
> Remove the use of this interrupt source in such a case. It's based on
> the first descriptor which holds the configuration for the whole
> linked list transfer.
>
> Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
> ---
> drivers/dma/at_xdmac.c | 13 ++++++++++++-
> 1 file changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
> index ec7a29d8e448..b558a23ffbc2 100644
> --- a/drivers/dma/at_xdmac.c
> +++ b/drivers/dma/at_xdmac.c
> @@ -308,6 +308,11 @@ static inline int at_xdmac_csize(u32 maxburst)
> return csize;
> };
>
> +static inline bool at_xdmac_chan_is_peripheral_xfer(u32 cfg)
> +{
> + return cfg & AT_XDMAC_CC_TYPE_PER_TRAN;
> +}
> +
> static inline u8 at_xdmac_get_dwidth(u32 cfg)
> {
> return (cfg & AT_XDMAC_CC_DWIDTH_MASK) >> AT_XDMAC_CC_DWIDTH_OFFSET;
> @@ -389,7 +394,13 @@ static void at_xdmac_start_xfer(struct at_xdmac_chan *atchan,
> at_xdmac_chan_read(atchan, AT_XDMAC_CUBC));
>
> at_xdmac_chan_write(atchan, AT_XDMAC_CID, 0xffffffff);
> - reg = AT_XDMAC_CIE_RBEIE | AT_XDMAC_CIE_WBEIE | AT_XDMAC_CIE_ROIE;
> + reg = AT_XDMAC_CIE_RBEIE | AT_XDMAC_CIE_WBEIE;
> + /*
> + * Request Overflow Error is only for peripheral synchronized transfers
> + */
> + if (at_xdmac_chan_is_peripheral_xfer(first->lld.mbr_cfg))
> + reg |= AT_XDMAC_CIE_ROIE;
> +
> /*
> * There is no end of list when doing cyclic dma, we need to get
> * an interrupt after each periods.
> --
> 2.17.1
>
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http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH 2/3] dmaengine: at_xdmac: enhance channel errors handling in tasklet
2019-02-05 11:03 ` [PATCH 2/3] dmaengine: at_xdmac: enhance channel errors handling " Nicolas Ferre
2019-02-05 12:33 ` Ludovic Desroches
@ 2019-02-11 11:58 ` Vinod Koul
2019-04-03 10:05 ` Nicolas.Ferre
1 sibling, 1 reply; 8+ messages in thread
From: Vinod Koul @ 2019-02-11 11:58 UTC (permalink / raw)
To: Nicolas Ferre
Cc: dmaengine, Ludovic Desroches, Alexandre Belloni,
linux-arm-kernel, linux-kernel
On 05-02-19, 12:03, Nicolas Ferre wrote:
> Complement the identification of errors with stoping the channel and
> dumping the descriptor that led to the error case.
>
> Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
> ---
> drivers/dma/at_xdmac.c | 43 ++++++++++++++++++++++++++++++++++++------
> 1 file changed, 37 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
> index 37a269420435..ec7a29d8e448 100644
> --- a/drivers/dma/at_xdmac.c
> +++ b/drivers/dma/at_xdmac.c
> @@ -1575,6 +1575,41 @@ static void at_xdmac_handle_cyclic(struct at_xdmac_chan *atchan)
> dmaengine_desc_get_callback_invoke(txd, NULL);
> }
>
> +static void at_xdmac_handle_error(struct at_xdmac_chan *atchan)
> +{
> + struct at_xdmac *atxdmac = to_at_xdmac(atchan->chan.device);
> + struct at_xdmac_desc *bad_desc;
> +
> + /*
> + * The descriptor currently at the head of the active list is
> + * broked. Since we don't have any way to report errors, we'll
You meant borked or broken...
> + * just have to scream loudly and try to carry on.
should we carry on or abort..?
> + */
> + if (atchan->irq_status & AT_XDMAC_CIS_RBEIS)
> + dev_err(chan2dev(&atchan->chan), "read bus error!!!");
> + if (atchan->irq_status & AT_XDMAC_CIS_WBEIS)
> + dev_err(chan2dev(&atchan->chan), "write bus error!!!");
> + if (atchan->irq_status & AT_XDMAC_CIS_ROIS)
> + dev_err(chan2dev(&atchan->chan), "request overflow error!!!");
> +
> + spin_lock_bh(&atchan->lock);
> + /* Channel must be disabled first as it's not done automatically */
> + at_xdmac_write(atxdmac, AT_XDMAC_GD, atchan->mask);
> + while (at_xdmac_read(atxdmac, AT_XDMAC_GS) & atchan->mask)
> + cpu_relax();
> + bad_desc = list_first_entry(&atchan->xfers_list,
> + struct at_xdmac_desc,
> + xfer_node);
> + spin_unlock_bh(&atchan->lock);
> + /* Print bad descriptor's details if needed */
Well this is not great to look and read at, please do consider adding
empty line before comments or logical blocks..
> + dev_dbg(chan2dev(&atchan->chan),
> + "%s: lld: mbr_sa=%pad, mbr_da=%pad, mbr_ubc=0x%08x\n",
> + __func__, &bad_desc->lld.mbr_sa, &bad_desc->lld.mbr_da,
> + bad_desc->lld.mbr_ubc);
not dev_err?
> +
> + /* Then continue with usual descriptor management */
> +}
> +
> static void at_xdmac_tasklet(unsigned long data)
> {
> struct at_xdmac_chan *atchan = (struct at_xdmac_chan *)data;
> @@ -1594,12 +1629,8 @@ static void at_xdmac_tasklet(unsigned long data)
> || (atchan->irq_status & error_mask)) {
> struct dma_async_tx_descriptor *txd;
>
> - if (atchan->irq_status & AT_XDMAC_CIS_RBEIS)
> - dev_err(chan2dev(&atchan->chan), "read bus error!!!");
> - if (atchan->irq_status & AT_XDMAC_CIS_WBEIS)
> - dev_err(chan2dev(&atchan->chan), "write bus error!!!");
> - if (atchan->irq_status & AT_XDMAC_CIS_ROIS)
> - dev_err(chan2dev(&atchan->chan), "request overflow error!!!");
> + if (atchan->irq_status & error_mask)
> + at_xdmac_handle_error(atchan);
>
> spin_lock(&atchan->lock);
> desc = list_first_entry(&atchan->xfers_list,
> --
> 2.17.1
--
~Vinod
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^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH 2/3] dmaengine: at_xdmac: enhance channel errors handling in tasklet
2019-02-11 11:58 ` Vinod Koul
@ 2019-04-03 10:05 ` Nicolas.Ferre
0 siblings, 0 replies; 8+ messages in thread
From: Nicolas.Ferre @ 2019-04-03 10:05 UTC (permalink / raw)
To: vkoul
Cc: dmaengine, Ludovic.Desroches, alexandre.belloni,
linux-arm-kernel, linux-kernel
Vinod,
Thanks for your review, I'm preparing v2.
On 11/02/2019 at 12:58, Vinod Koul wrote:
> On 05-02-19, 12:03, Nicolas Ferre wrote:
>> Complement the identification of errors with stoping the channel and
>> dumping the descriptor that led to the error case.
>>
>> Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
>> ---
>> drivers/dma/at_xdmac.c | 43 ++++++++++++++++++++++++++++++++++++------
>> 1 file changed, 37 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
>> index 37a269420435..ec7a29d8e448 100644
>> --- a/drivers/dma/at_xdmac.c
>> +++ b/drivers/dma/at_xdmac.c
>> @@ -1575,6 +1575,41 @@ static void at_xdmac_handle_cyclic(struct at_xdmac_chan *atchan)
>> dmaengine_desc_get_callback_invoke(txd, NULL);
>> }
>>
>> +static void at_xdmac_handle_error(struct at_xdmac_chan *atchan)
>> +{
>> + struct at_xdmac *atxdmac = to_at_xdmac(atchan->chan.device);
>> + struct at_xdmac_desc *bad_desc;
>> +
>> + /*
>> + * The descriptor currently at the head of the active list is
>> + * broked. Since we don't have any way to report errors, we'll
>
> You meant borked or broken...
Broken
>
>> + * just have to scream loudly and try to carry on.
>
> should we carry on or abort..?
Changed in:
* just have to scream loudly and try to continue with other
* descriptors queued (if any).
>> + */
>> + if (atchan->irq_status & AT_XDMAC_CIS_RBEIS)
>> + dev_err(chan2dev(&atchan->chan), "read bus error!!!");
>> + if (atchan->irq_status & AT_XDMAC_CIS_WBEIS)
>> + dev_err(chan2dev(&atchan->chan), "write bus error!!!");
>> + if (atchan->irq_status & AT_XDMAC_CIS_ROIS)
>> + dev_err(chan2dev(&atchan->chan), "request overflow error!!!");
>> +
>> + spin_lock_bh(&atchan->lock);
>> + /* Channel must be disabled first as it's not done automatically */
>> + at_xdmac_write(atxdmac, AT_XDMAC_GD, atchan->mask);
>> + while (at_xdmac_read(atxdmac, AT_XDMAC_GS) & atchan->mask)
>> + cpu_relax();
>> + bad_desc = list_first_entry(&atchan->xfers_list,
>> + struct at_xdmac_desc,
>> + xfer_node);
>> + spin_unlock_bh(&atchan->lock);
>> + /* Print bad descriptor's details if needed */
>
> Well this is not great to look and read at, please do consider adding
> empty line before comments or logical blocks..
True, indeed.
>> + dev_dbg(chan2dev(&atchan->chan),
>> + "%s: lld: mbr_sa=%pad, mbr_da=%pad, mbr_ubc=0x%08x\n",
>> + __func__, &bad_desc->lld.mbr_sa, &bad_desc->lld.mbr_da,
>> + bad_desc->lld.mbr_ubc);
>
> not dev_err?
Well, we have the dev_err at the beginning of the function, I think it's
enough: this is really debugging information that needs to be activated
to track the DMA configuration bug: it's not meant for production.
>> +
>> + /* Then continue with usual descriptor management */
>> +}
>> +
>> static void at_xdmac_tasklet(unsigned long data)
>> {
>> struct at_xdmac_chan *atchan = (struct at_xdmac_chan *)data;
>> @@ -1594,12 +1629,8 @@ static void at_xdmac_tasklet(unsigned long data)
>> || (atchan->irq_status & error_mask)) {
>> struct dma_async_tx_descriptor *txd;
>>
>> - if (atchan->irq_status & AT_XDMAC_CIS_RBEIS)
>> - dev_err(chan2dev(&atchan->chan), "read bus error!!!");
>> - if (atchan->irq_status & AT_XDMAC_CIS_WBEIS)
>> - dev_err(chan2dev(&atchan->chan), "write bus error!!!");
>> - if (atchan->irq_status & AT_XDMAC_CIS_ROIS)
>> - dev_err(chan2dev(&atchan->chan), "request overflow error!!!");
>> + if (atchan->irq_status & error_mask)
>> + at_xdmac_handle_error(atchan);
>>
>> spin_lock(&atchan->lock);
>> desc = list_first_entry(&atchan->xfers_list,
>> --
>> 2.17.1
>
--
Nicolas Ferre
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^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2019-04-03 10:05 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-02-05 11:03 [PATCH 1/3] dmaengine: at_xdmac: remove BUG_ON macro in tasklet Nicolas Ferre
2019-02-05 11:03 ` [PATCH 2/3] dmaengine: at_xdmac: enhance channel errors handling " Nicolas Ferre
2019-02-05 12:33 ` Ludovic Desroches
2019-02-11 11:58 ` Vinod Koul
2019-04-03 10:05 ` Nicolas.Ferre
2019-02-05 11:03 ` [PATCH 3/3] dmaengine: at_xdmac: only monitor overflow errors for peripheral xfer Nicolas Ferre
2019-02-05 12:35 ` Ludovic Desroches
2019-02-05 12:30 ` [PATCH 1/3] dmaengine: at_xdmac: remove BUG_ON macro in tasklet Ludovic Desroches
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