From: sricharan@codeaurora.org (Sricharan)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 2/2] i2c: qup: Fixed the DMA segments length
Date: Wed, 11 May 2016 21:48:20 +0530 [thread overview]
Message-ID: <000b01d1aba0$c2fea380$48fbea80$@codeaurora.org> (raw)
In-Reply-To: <1462797871-8595-3-git-send-email-absahu@codeaurora.org>
Hi,
> 1. The current QCOM I2C driver code is failing for transfer length greater
> than 255. This is happening due to improper segments length as the I2C DMA
> segments can be maximum of 256 bytes.
>
> 2. The transfer length tlen was being initialized with 0 for 256 bytes,
which is
> being passed for DMA mappings resulting in improper DMA mapping length.
>
> This patch fixes the above said problems by initializing the block count
with
> the values calculated in qup_i2c_set_blk_data and calculating the
remaining
> length for last DMA segment. Also, the block data length need to be
> decremented after each transfer. Additionally, this patch corrects the
tlen
> assignment for DMA mapping.
>
> Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
> ---
> drivers/i2c/busses/i2c-qup.c | 12 +++++++-----
> 1 file changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c
index
> 8c2f1bc..6d6b7dc 100644
> --- a/drivers/i2c/busses/i2c-qup.c
> +++ b/drivers/i2c/busses/i2c-qup.c
> @@ -651,23 +651,24 @@ static int qup_i2c_bam_do_xfer(struct
> qup_i2c_dev *qup, struct i2c_msg *msg,
> u8 *tags;
>
> while (idx < num) {
> - blocks = (msg->len + limit) / limit;
> - rem = msg->len % limit;
> tx_len = 0, len = 0, i = 0;
>
> qup->is_last = (idx == (num - 1));
>
> qup_i2c_set_blk_data(qup, msg);
>
> + blocks = qup->blk.count;
> + rem = msg->len - (blocks - 1) * limit;
> +
Same if we had blocks = (msg->len + limit - 1) / limit instead of the
above ?
Otherwise,
Reviewed-by: Sricharan at codeaurora.org
Regards,
Sricharan
next prev parent reply other threads:[~2016-05-11 16:18 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-09 12:44 [PATCH 0/2] i2c: qup: Fixed the DMA transfer errors Abhishek Sahu
2016-05-09 12:44 ` [PATCH 1/2] i2c: qup: Cleared the error bits in ISR Abhishek Sahu
2016-05-11 15:57 ` Sricharan
2016-05-11 17:34 ` Abhishek Sahu
2016-05-12 2:28 ` Sricharan
2016-05-12 5:13 ` Andy Gross
2016-05-12 6:18 ` Abhishek Sahu
2016-05-12 17:58 ` Andy Gross
2016-05-12 19:32 ` Abhishek Sahu
2016-05-12 20:05 ` Andy Gross
2016-05-12 20:27 ` Abhishek Sahu
2016-06-18 16:32 ` Wolfram Sang
2016-06-20 12:48 ` Abhishek Sahu
2016-07-15 6:33 ` Wolfram Sang
2016-05-09 12:44 ` [PATCH 2/2] i2c: qup: Fixed the DMA segments length Abhishek Sahu
2016-05-11 16:18 ` Sricharan [this message]
2016-05-11 17:43 ` Abhishek Sahu
2016-07-15 6:38 ` Wolfram Sang
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