[media] marvell-cam: Make suspend/resume work on MMP2
Somehow I didn't ever quite get around to implementing suspend/resume on
the MMP2 platform; this patch fixes that little oversight. A bit of core
work was necessary to do the right thing in the s/g DMA case.
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/marvell-ccic/mcam-core.c b/drivers/media/video/marvell-ccic/mcam-core.c
index 80ec64d..c1f12f9 100644
--- a/drivers/media/video/marvell-ccic/mcam-core.c
+++ b/drivers/media/video/marvell-ccic/mcam-core.c
@@ -522,6 +522,15 @@
*/
static void mcam_ctlr_dma_sg(struct mcam_camera *cam)
{
+ /*
+ * The list-empty condition can hit us at resume time
+ * if the buffer list was empty when the system was suspended.
+ */
+ if (list_empty(&cam->buffers)) {
+ set_bit(CF_SG_RESTART, &cam->flags);
+ return;
+ }
+
mcam_reg_clear_bit(cam, REG_CTRL1, C1_DESC_3WORD);
mcam_sg_next_buffer(cam);
mcam_reg_set_bit(cam, REG_CTRL1, C1_DESC_ENA);
@@ -566,6 +575,7 @@
} else {
set_bit(CF_SG_RESTART, &cam->flags);
singles++;
+ cam->vb_bufs[0] = NULL;
}
/*
* Now we can give the completed frame back to user space.
@@ -661,10 +671,10 @@
unsigned long flags;
spin_lock_irqsave(&cam->dev_lock, flags);
+ clear_bit(CF_SG_RESTART, &cam->flags);
cam->dma_setup(cam);
mcam_ctlr_image(cam);
mcam_set_config_needed(cam, 0);
- clear_bit(CF_SG_RESTART, &cam->flags);
spin_unlock_irqrestore(&cam->dev_lock, flags);
return 0;
}
@@ -873,7 +883,8 @@
mcam_reset_buffers(cam);
mcam_ctlr_irq_enable(cam);
cam->state = S_STREAMING;
- mcam_ctlr_start(cam);
+ if (!test_bit(CF_SG_RESTART, &cam->flags))
+ mcam_ctlr_start(cam);
spin_unlock_irqrestore(&cam->dev_lock, flags);
return 0;
}
@@ -1818,11 +1829,15 @@
void mccic_suspend(struct mcam_camera *cam)
{
- enum mcam_state cstate = cam->state;
+ mutex_lock(&cam->s_mutex);
+ if (cam->users > 0) {
+ enum mcam_state cstate = cam->state;
- mcam_ctlr_stop_dma(cam);
- mcam_ctlr_power_down(cam);
- cam->state = cstate;
+ mcam_ctlr_stop_dma(cam);
+ mcam_ctlr_power_down(cam);
+ cam->state = cstate;
+ }
+ mutex_unlock(&cam->s_mutex);
}
int mccic_resume(struct mcam_camera *cam)
@@ -1839,8 +1854,15 @@
mutex_unlock(&cam->s_mutex);
set_bit(CF_CONFIG_NEEDED, &cam->flags);
- if (cam->state == S_STREAMING)
+ if (cam->state == S_STREAMING) {
+ /*
+ * If there was a buffer in the DMA engine at suspend
+ * time, put it back on the queue or we'll forget about it.
+ */
+ if (cam->buffer_mode == B_DMA_sg && cam->vb_bufs[0])
+ list_add(&cam->vb_bufs[0]->queue, &cam->buffers);
ret = mcam_read_setup(cam);
+ }
return ret;
}
#endif /* CONFIG_PM */