Re: [PATCH 01/12] i2c: qup: fixed releasing dma without flush operation completion

From: Abhishek Sahu
Date: Mon Feb 19 2018 - 05:24:18 EST


On 2018-02-08 19:33, Sricharan R wrote:
Hi Abhishek,

On 2/3/2018 1:28 PM, Abhishek Sahu wrote:
The QUP BSLP BAM generates the following error sometimes if the
current I2C DMA transfer fails and the flush operation has been
scheduled

âbam-dma-engine 7884000.dma: Cannot free busy channelâ

If any I2C error comes during BAM DMA transfer, then the QUP I2C
interrupt will be generated and the flush operation will be
carried out to make i2c consume all scheduled DMA transfer.
Currently, the same completion structure is being used for BAM
transfer which has already completed without reinit. It will make
flush operation wait_for_completion_timeout completed immediately
and will proceed for freeing the DMA resources where the
descriptors are still in process.

Signed-off-by: Abhishek Sahu <absahu@xxxxxxxxxxxxxx>
---
drivers/i2c/busses/i2c-qup.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c
index 08f8e01..9faa26c41a 100644
--- a/drivers/i2c/busses/i2c-qup.c
+++ b/drivers/i2c/busses/i2c-qup.c
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2009-2013, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2009-2013, 2016-2018, The Linux Foundation. All rights reserved.

Not sure, if this was an intended change. But given that you are fixing this,

Thanks Sricharan.
Since this is the first patch, so I updated the year.

you can change the header to the new SPDX one.


Yes that would be better.
I will fix that also.

Thanks,
Abhishek

* Copyright (c) 2014, Sony Mobile Communications AB.
*
*
@@ -844,6 +844,8 @@ static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, struct i2c_msg *msg,
}

if (ret || qup->bus_err || qup->qup_err) {
+ reinit_completion(&qup->xfer);
+
if (qup_i2c_change_state(qup, QUP_RUN_STATE)) {
dev_err(qup->dev, "change to run state timed out");
goto desc_err;


Except for the above nit,
Acked-by: Sricharan R <sricharan@xxxxxxxxxxxxxx>

Regards,
Sricharan