From: <Nicolas.Ferre@microchip.com>
To: <vkoul@kernel.org>
Cc: dmaengine@vger.kernel.org, Ludovic.Desroches@microchip.com,
alexandre.belloni@bootlin.com,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/3] dmaengine: at_xdmac: enhance channel errors handling in tasklet
Date: Wed, 3 Apr 2019 10:05:00 +0000 [thread overview]
Message-ID: <1cdc51b6-3b0b-ee17-855a-ebd3896059ba@microchip.com> (raw)
In-Reply-To: <20190211115834.GS4296@vkoul-mobl>
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
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2019-04-03 10:05 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
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 [this message]
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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1cdc51b6-3b0b-ee17-855a-ebd3896059ba@microchip.com \
--to=nicolas.ferre@microchip.com \
--cc=Ludovic.Desroches@microchip.com \
--cc=alexandre.belloni@bootlin.com \
--cc=dmaengine@vger.kernel.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=vkoul@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).