fcabdb9b9d
These are cherry-picked & backported from LKML: *https://lkml.org/lkml/2015/3/17/19 They are enabled on both 3.18 and 4.1 kernel. Patches 150 to 154 are applying changes merged since 3.18; they enable mechanisms used by the ADM driver. ADM engine is used by the NAND controller, so it is necessary to bring-up NAND flash support. Signed-off-by: Mathieu Olivari <mathieu@codeaurora.org> SVN-Revision: 46567
71 lines
1.8 KiB
Diff
71 lines
1.8 KiB
Diff
From d2f4f99db3e9ec8b063cf2e45704e2bb95428317 Mon Sep 17 00:00:00 2001
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From: Maxime Ripard <maxime.ripard@free-electrons.com>
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Date: Mon, 17 Nov 2014 14:41:58 +0100
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Subject: [PATCH] dmaengine: Rework dma_chan_get
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dma_chan_get uses a rather interesting error handling and code path.
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Change it to something more usual in the kernel.
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Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
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Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
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Signed-off-by: Vinod Koul <vinod.koul@intel.com>
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---
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drivers/dma/dmaengine.c | 36 +++++++++++++++++++-----------------
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1 file changed, 19 insertions(+), 17 deletions(-)
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--- a/drivers/dma/dmaengine.c
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+++ b/drivers/dma/dmaengine.c
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@@ -222,31 +222,33 @@ static void balance_ref_count(struct dma
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*/
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static int dma_chan_get(struct dma_chan *chan)
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{
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- int err = -ENODEV;
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struct module *owner = dma_chan_to_owner(chan);
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+ int ret;
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+ /* The channel is already in use, update client count */
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if (chan->client_count) {
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__module_get(owner);
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- err = 0;
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- } else if (try_module_get(owner))
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- err = 0;
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+ goto out;
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+ }
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- if (err == 0)
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- chan->client_count++;
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+ if (!try_module_get(owner))
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+ return -ENODEV;
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/* allocate upon first client reference */
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- if (chan->client_count == 1 && err == 0) {
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- int desc_cnt = chan->device->device_alloc_chan_resources(chan);
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-
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- if (desc_cnt < 0) {
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- err = desc_cnt;
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- chan->client_count = 0;
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- module_put(owner);
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- } else if (!dma_has_cap(DMA_PRIVATE, chan->device->cap_mask))
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- balance_ref_count(chan);
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- }
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-
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- return err;
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+ ret = chan->device->device_alloc_chan_resources(chan);
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+ if (ret < 0)
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+ goto err_out;
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+
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+ if (!dma_has_cap(DMA_PRIVATE, chan->device->cap_mask))
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+ balance_ref_count(chan);
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+
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+out:
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+ chan->client_count++;
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+ return 0;
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+
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+err_out:
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+ module_put(owner);
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+ return ret;
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}
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/**
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