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drivers: dma: intel_adsp_gpdma: fix issue with stop and PM refcounts

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The DMA interface allows start and stop to be called multiple
times and driver should ensure nothing bad happens if the calls
are not balanced.

Fix an issue where after a start-stop sequence the DMA would be
powered down, and then a subsequent stop would result in a crash
as driver accesses registers of a powered down hardware block.

Fix the issue by handling stop without actually reading the hw
registers to check channel status.

Link: https://github.com/thesofproject/sof/issues/8503
Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
This commit is contained in:
Kai Vehmanen 2023-11-28 18:28:05 +02:00 committed by Fabio Baltieri
parent f473bd9be1
commit c7e3ccd51a
1 changed files with 12 additions and 0 deletions
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12
drivers/dma/dma_dw_common.c
View file

@ -12,6 +12,7 @@
#include <zephyr/device.h>
#include <zephyr/init.h>
#include <zephyr/drivers/dma.h>
#include <zephyr/pm/device.h>
#include <zephyr/pm/device_runtime.h>
#include <soc.h>
#include "dma_dw_common.h"
@ -546,6 +547,7 @@ int dw_dma_stop(const struct device *dev, uint32_t channel)
const struct dw_dma_dev_cfg *const dev_cfg = dev->config;
struct dw_dma_dev_data *dev_data = dev->data;
struct dw_dma_chan_data *chan_data = &dev_data->chan[channel];
enum pm_device_state pm_state;
int ret = 0;
if (channel >= DW_CHAN_COUNT) {
@ -553,7 +555,17 @@ int dw_dma_stop(const struct device *dev, uint32_t channel)
goto out;
}
/*
* skip if device is not active. if we get an error for state_get,
* do not skip but check actual hardware state and stop if
* needed
*/
ret = pm_device_state_get(dev, &pm_state);
if (!ret && pm_state != PM_DEVICE_STATE_ACTIVE)
goto out;
if (!dw_dma_is_enabled(dev, channel) && chan_data->state != DW_DMA_SUSPENDED) {
ret = 0;
goto out;
}