[RFC 13/19] HSI: omap_ssi_port: avoid pm_runtime_get_sync in ssi_start_dma and ssi_start_pio

[Sebastian Reichel]

These functions may be called from atomic context,
so avoid synchronous runtime pm calls.

Signed-off-by: Sebastian Reichel <s...@kernel.org>
---
 drivers/hsi/controllers/omap_ssi_port.c | 30 ++++++++++++++++++++++++------
 1 file changed, 24 insertions(+), 6 deletions(-)

diff --git a/drivers/hsi/controllers/omap_ssi_port.c 
b/drivers/hsi/controllers/omap_ssi_port.c
index f62f0c482cea..f7ed59ba3b2c 100644
--- a/drivers/hsi/controllers/omap_ssi_port.c
+++ b/drivers/hsi/controllers/omap_ssi_port.c
@@ -225,11 +225,21 @@ static int ssi_start_dma(struct hsi_msg *msg, int lch)
        u32 d_addr;
        u32 tmp;
 
+       /* Hold clocks during the transfer */
+       pm_runtime_get(omap_port->pdev);
+
+       if (!pm_runtime_active(omap_port->pdev)) {
+               dev_warn(&port->device, "ssi_start_dma called without runtime 
PM!\n");
+               pm_runtime_put(omap_port->pdev);
+               return -EREMOTEIO;
+       }
+
        if (msg->ttype == HSI_MSG_READ) {
                err = dma_map_sg(&ssi->device, msg->sgt.sgl, msg->sgt.nents,
                                                        DMA_FROM_DEVICE);
                if (err < 0) {
                        dev_dbg(&ssi->device, "DMA map SG failed !\n");
+                       pm_runtime_put(omap_port->pdev);
                        return err;
                }
                csdp = SSI_DST_BURST_4x32_BIT | SSI_DST_MEMORY_PORT |
@@ -246,6 +256,7 @@ static int ssi_start_dma(struct hsi_msg *msg, int lch)
                                                        DMA_TO_DEVICE);
                if (err < 0) {
                        dev_dbg(&ssi->device, "DMA map SG failed !\n");
+                       pm_runtime_put(omap_port->pdev);
                        return err;
                }
                csdp = SSI_SRC_BURST_4x32_BIT | SSI_SRC_MEMORY_PORT |
@@ -261,9 +272,6 @@ static int ssi_start_dma(struct hsi_msg *msg, int lch)
        dev_dbg(&ssi->device, "lch %d cdsp %08x ccr %04x s_addr %08x d_addr 
%08x\n",
                lch, csdp, ccr, s_addr, d_addr);
 
-       /* Hold clocks during the transfer */
-       pm_runtime_get_sync(omap_port->pdev);
-
        writew_relaxed(csdp, gdd + SSI_GDD_CSDP_REG(lch));
        writew_relaxed(SSI_BLOCK_IE | SSI_TOUT_IE, gdd + SSI_GDD_CICR_REG(lch));
        writel_relaxed(d_addr, gdd + SSI_GDD_CDSA_REG(lch));
@@ -290,11 +298,18 @@ static int ssi_start_pio(struct hsi_msg *msg)
        struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
        u32 val;
 
-       pm_runtime_get_sync(omap_port->pdev);
+       pm_runtime_get(omap_port->pdev);
+
+       if (!pm_runtime_active(omap_port->pdev)) {
+               dev_warn(&port->device, "ssi_start_pio called without runtime 
PM!\n");
+               pm_runtime_put(omap_port->pdev);
+               return -EREMOTEIO;
+       }
+
        if (msg->ttype == HSI_MSG_WRITE) {
                val = SSI_DATAACCEPT(msg->channel);
                /* Hold clocks for pio writes */
-               pm_runtime_get_sync(omap_port->pdev);
+               pm_runtime_get(omap_port->pdev);
        } else {
                val = SSI_DATAAVAILABLE(msg->channel) | SSI_ERROROCCURED;
        }
@@ -302,7 +317,7 @@ static int ssi_start_pio(struct hsi_msg *msg)
                                                msg->ttype ? "write" : "read");
        val |= readl(omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
        writel(val, omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
-       pm_runtime_put_sync(omap_port->pdev);
+       pm_runtime_put(omap_port->pdev);
        msg->actual_len = 0;
        msg->status = HSI_STATUS_PROCEEDING;
 
@@ -388,6 +403,8 @@ static int ssi_async(struct hsi_msg *msg)
                queue = &omap_port->rxqueue[msg->channel];
        }
        msg->status = HSI_STATUS_QUEUED;
+
+       pm_runtime_get_sync(omap_port->pdev);
        spin_lock_bh(&omap_port->lock);
        list_add_tail(&msg->link, queue);
        err = ssi_start_transfer(queue);
@@ -396,6 +413,7 @@ static int ssi_async(struct hsi_msg *msg)
                msg->status = HSI_STATUS_ERROR;
        }
        spin_unlock_bh(&omap_port->lock);
+       pm_runtime_put(omap_port->pdev);
        dev_dbg(&port->device, "msg status %d ttype %d ch %d\n",
                                msg->status, msg->ttype, msg->channel);
 
-- 
2.8.1