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author | Sricharan R <sricharan@codeaurora.org> | 2016-06-10 23:38:19 +0530 |
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committer | Wolfram Sang <wsa@the-dreams.de> | 2016-06-18 18:15:52 +0200 |
commit | 685983f4decc5fa5700a0ab083859a2fe59acf10 (patch) | |
tree | fc2ceba31234b129701fa60d9a381375ee9ad022 /drivers/i2c/busses/i2c-qup.c | |
parent | a02f3d081a79ec702b85b9c1a91edf770cf1eab2 (diff) | |
download | op-kernel-dev-685983f4decc5fa5700a0ab083859a2fe59acf10.zip op-kernel-dev-685983f4decc5fa5700a0ab083859a2fe59acf10.tar.gz |
i2c: qup: Fix broken dma when CONFIG_DEBUG_SG is enabled
With CONFIG_DEBUG_SG is enabled and when dma mode is used, below dump is seen,
------------[ cut here ]------------
kernel BUG at include/linux/scatterlist.h:140!
Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.4.0-00459-g9f087b9-dirty #7
Hardware name: Qualcomm Technologies, Inc. APQ 8016 SBC (DT)
task: ffffffc036868000 ti: ffffffc036870000 task.ti: ffffffc036870000
PC is at qup_sg_set_buf.isra.13+0x138/0x154
LR is at qup_sg_set_buf.isra.13+0x50/0x154
pc : [<ffffffc0005a0ed8>] lr : [<ffffffc0005a0df0>] pstate: 60000145
sp : ffffffc0368735c0
x29: ffffffc0368735c0 x28: ffffffc036873752
x27: ffffffc035233018 x26: ffffffc000c4e000
x25: 0000000000000000 x24: 0000000000000004
x23: 0000000000000000 x22: ffffffc035233668
x21: ffffff80004e3000 x20: ffffffc0352e0018
x19: 0000004000000000 x18: 0000000000000028
x17: 0000000000000004 x16: ffffffc0017a39c8
x15: 0000000000001cdf x14: ffffffc0019929d8
x13: ffffffc0352e0018 x12: 0000000000000000
x11: 0000000000000001 x10: 0000000000000001
x9 : ffffffc0012b2d70 x8 : ffffff80004e3000
x7 : 0000000000000018 x6 : 0000000030000000
x5 : ffffffc00199f018 x4 : ffffffc035233018
x3 : 0000000000000004 x2 : 00000000c0000000
x1 : 0000000000000003 x0 : 0000000000000000
Process swapper/0 (pid: 1, stack limit = 0xffffffc036870020)
Stack: (0xffffffc0368735c0 to 0xffffffc036874000)
sg_set_bug expects that the buf parameter passed in should be from
lowmem and a valid pageframe. This is not true for pages from
dma_alloc_coherent which can be carveouts, hence the check fails.
Change allocation of sg buffers from dma_coherent memory to kzalloc
to fix the issue. Note that now dma_map/unmap is used to make the
kzalloc'ed buffers coherent before passing it to the dmaengine.
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Reviewed-by: Andy Gross <andy.gross@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c/busses/i2c-qup.c')
-rw-r--r-- | drivers/i2c/busses/i2c-qup.c | 51 |
1 files changed, 15 insertions, 36 deletions
diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c index cc6439a..43adc2d 100644 --- a/drivers/i2c/busses/i2c-qup.c +++ b/drivers/i2c/busses/i2c-qup.c @@ -585,8 +585,8 @@ static void qup_i2c_bam_cb(void *data) } static int qup_sg_set_buf(struct scatterlist *sg, void *buf, - struct qup_i2c_tag *tg, unsigned int buflen, - struct qup_i2c_dev *qup, int map, int dir) + unsigned int buflen, struct qup_i2c_dev *qup, + int dir) { int ret; @@ -595,9 +595,6 @@ static int qup_sg_set_buf(struct scatterlist *sg, void *buf, if (!ret) return -EINVAL; - if (!map) - sg_dma_address(sg) = tg->addr + ((u8 *)buf - tg->start); - return 0; } @@ -670,16 +667,15 @@ static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, struct i2c_msg *msg, /* scratch buf to read the start and len tags */ ret = qup_sg_set_buf(&qup->brx.sg[rx_buf++], &qup->brx.tag.start[0], - &qup->brx.tag, - 2, qup, 0, 0); + 2, qup, DMA_FROM_DEVICE); if (ret) return ret; ret = qup_sg_set_buf(&qup->brx.sg[rx_buf++], &msg->buf[limit * i], - NULL, tlen, qup, - 1, DMA_FROM_DEVICE); + tlen, qup, + DMA_FROM_DEVICE); if (ret) return ret; @@ -688,7 +684,7 @@ static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, struct i2c_msg *msg, } ret = qup_sg_set_buf(&qup->btx.sg[tx_buf++], &qup->start_tag.start[off], - &qup->start_tag, len, qup, 0, 0); + len, qup, DMA_TO_DEVICE); if (ret) return ret; @@ -696,8 +692,7 @@ static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, struct i2c_msg *msg, /* scratch buf to read the BAM EOT and FLUSH tags */ ret = qup_sg_set_buf(&qup->brx.sg[rx_buf++], &qup->brx.tag.start[0], - &qup->brx.tag, 2, - qup, 0, 0); + 2, qup, DMA_FROM_DEVICE); if (ret) return ret; } else { @@ -709,17 +704,15 @@ static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, struct i2c_msg *msg, len = qup_i2c_set_tags(tags, qup, msg, 1); ret = qup_sg_set_buf(&qup->btx.sg[tx_buf++], - tags, - &qup->start_tag, len, - qup, 0, 0); + tags, len, + qup, DMA_TO_DEVICE); if (ret) return ret; tx_len += len; ret = qup_sg_set_buf(&qup->btx.sg[tx_buf++], &msg->buf[limit * i], - NULL, tlen, qup, 1, - DMA_TO_DEVICE); + tlen, qup, DMA_TO_DEVICE); if (ret) return ret; i++; @@ -738,8 +731,7 @@ static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, struct i2c_msg *msg, QUP_BAM_FLUSH_STOP; ret = qup_sg_set_buf(&qup->btx.sg[tx_buf++], &qup->btx.tag.start[0], - &qup->btx.tag, len, - qup, 0, 0); + len, qup, DMA_TO_DEVICE); if (ret) return ret; tx_nents += 1; @@ -1407,27 +1399,21 @@ static int qup_i2c_probe(struct platform_device *pdev) /* 2 tag bytes for each block + 5 for start, stop tags */ size = blocks * 2 + 5; - qup->dpool = dma_pool_create("qup_i2c-dma-pool", &pdev->dev, - size, 4, 0); - qup->start_tag.start = dma_pool_alloc(qup->dpool, GFP_KERNEL, - &qup->start_tag.addr); + qup->start_tag.start = devm_kzalloc(&pdev->dev, + size, GFP_KERNEL); if (!qup->start_tag.start) { ret = -ENOMEM; goto fail_dma; } - qup->brx.tag.start = dma_pool_alloc(qup->dpool, - GFP_KERNEL, - &qup->brx.tag.addr); + qup->brx.tag.start = devm_kzalloc(&pdev->dev, 2, GFP_KERNEL); if (!qup->brx.tag.start) { ret = -ENOMEM; goto fail_dma; } - qup->btx.tag.start = dma_pool_alloc(qup->dpool, - GFP_KERNEL, - &qup->btx.tag.addr); + qup->btx.tag.start = devm_kzalloc(&pdev->dev, 2, GFP_KERNEL); if (!qup->btx.tag.start) { ret = -ENOMEM; goto fail_dma; @@ -1566,13 +1552,6 @@ static int qup_i2c_remove(struct platform_device *pdev) struct qup_i2c_dev *qup = platform_get_drvdata(pdev); if (qup->is_dma) { - dma_pool_free(qup->dpool, qup->start_tag.start, - qup->start_tag.addr); - dma_pool_free(qup->dpool, qup->brx.tag.start, - qup->brx.tag.addr); - dma_pool_free(qup->dpool, qup->btx.tag.start, - qup->btx.tag.addr); - dma_pool_destroy(qup->dpool); dma_release_channel(qup->btx.dma); dma_release_channel(qup->brx.dma); } |