c7bf2accc9
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
|
|
From: Maxime Ripard <maxime.ripard@free-electrons.com>
|
|
Date: Mon, 17 Nov 2014 14:41:58 +0100
|
|
Subject: [PATCH] dmaengine: Rework dma_chan_get
|
|
|
|
dma_chan_get uses a rather interesting error handling and code path.
|
|
|
|
Change it to something more usual in the kernel.
|
|
|
|
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
|
|
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
|
|
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
|
|
---
|
|
drivers/dma/dmaengine.c | 36 +++++++++++++++++++-----------------
|
|
1 file changed, 19 insertions(+), 17 deletions(-)
|
|
|
|
--- a/drivers/dma/dmaengine.c
|
|
+++ b/drivers/dma/dmaengine.c
|
|
@@ -222,31 +222,33 @@ static void balance_ref_count(struct dma
|
|
*/
|
|
static int dma_chan_get(struct dma_chan *chan)
|
|
{
|
|
- int err = -ENODEV;
|
|
struct module *owner = dma_chan_to_owner(chan);
|
|
+ int ret;
|
|
|
|
+ /* The channel is already in use, update client count */
|
|
if (chan->client_count) {
|
|
__module_get(owner);
|
|
- err = 0;
|
|
- } else if (try_module_get(owner))
|
|
- err = 0;
|
|
+ goto out;
|
|
+ }
|
|
|
|
- if (err == 0)
|
|
- chan->client_count++;
|
|
+ if (!try_module_get(owner))
|
|
+ return -ENODEV;
|
|
|
|
/* allocate upon first client reference */
|
|
- if (chan->client_count == 1 && err == 0) {
|
|
- int desc_cnt = chan->device->device_alloc_chan_resources(chan);
|
|
-
|
|
- if (desc_cnt < 0) {
|
|
- err = desc_cnt;
|
|
- chan->client_count = 0;
|
|
- module_put(owner);
|
|
- } else if (!dma_has_cap(DMA_PRIVATE, chan->device->cap_mask))
|
|
- balance_ref_count(chan);
|
|
- }
|
|
-
|
|
- return err;
|
|
+ ret = chan->device->device_alloc_chan_resources(chan);
|
|
+ if (ret < 0)
|
|
+ goto err_out;
|
|
+
|
|
+ if (!dma_has_cap(DMA_PRIVATE, chan->device->cap_mask))
|
|
+ balance_ref_count(chan);
|
|
+
|
|
+out:
|
|
+ chan->client_count++;
|
|
+ return 0;
|
|
+
|
|
+err_out:
|
|
+ module_put(owner);
|
|
+ return ret;
|
|
}
|
|
|
|
/**
|