dmaengine: dma: imx-sdma: add fw_loaded and is_ram_script

Add 'fw_loaded' and 'is_ram_script' to check if the script used by channel
is ram script and it's loaded or not, so that could prevent meaningless
following malloc dma descriptor and bd allocate in sdma_transfer_init(),
otherwise memory may be consumed out potentially without free in case
that spi fallback into pio while dma transfer failed by sdma firmware not
ready(next ERR009165 patch depends on sdma RAM scripts/firmware).
Signed-off-by: Robin Gong <yibin.gong@nxp.com>
Acked-by: Vinod Koul <vkoul@kernel.org>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

drivers/dma/imx-sdma.c

@@ -435,6 +435,7 @@ struct sdma_channel {
 	enum dma_status			status;
 	struct imx_dma_data		data;
 	struct work_struct		terminate_worker;
+	bool				is_ram_script;
 };
 
 #define IMX_DMA_SG_LOOP		BIT(0)
@@ -498,6 +499,7 @@ struct sdma_engine {
 	struct sdma_buffer_descriptor	*bd0;
 	/* clock ratio for AHB:SDMA core. 1:1 is 1, 2:1 is 0*/
 	bool				clk_ratio;
+	bool                            fw_loaded;
 };
 
 static int sdma_config_write(struct dma_chan *chan,
@@ -918,6 +920,7 @@ static void sdma_get_pc(struct sdma_channel *sdmac,
 	sdmac->pc_to_device = 0;
 	sdmac->device_to_device = 0;
 	sdmac->pc_to_pc = 0;
+	sdmac->is_ram_script = false;
 
 	switch (peripheral_type) {
 	case IMX_DMATYPE_MEMORY:
@@ -953,6 +956,7 @@ static void sdma_get_pc(struct sdma_channel *sdmac,
 	case IMX_DMATYPE_SSI_DUAL:
 		per_2_emi = sdma->script_addrs->ssish_2_mcu_addr;
 		emi_2_per = sdma->script_addrs->mcu_2_ssish_addr;
+		sdmac->is_ram_script = true;
 		break;
 	case IMX_DMATYPE_SSI_SP:
 	case IMX_DMATYPE_MMC:
@@ -967,6 +971,7 @@ static void sdma_get_pc(struct sdma_channel *sdmac,
 		per_2_emi = sdma->script_addrs->asrc_2_mcu_addr;
 		emi_2_per = sdma->script_addrs->asrc_2_mcu_addr;
 		per_2_per = sdma->script_addrs->per_2_per_addr;
+		sdmac->is_ram_script = true;
 		break;
 	case IMX_DMATYPE_ASRC_SP:
 		per_2_emi = sdma->script_addrs->shp_2_mcu_addr;
@@ -1363,6 +1368,11 @@ static struct sdma_desc *sdma_transfer_init(struct sdma_channel *sdmac,
 {
 	struct sdma_desc *desc;
 
+	if (!sdmac->sdma->fw_loaded && sdmac->is_ram_script) {
+		dev_warn_once(sdmac->sdma->dev, "sdma firmware not ready!\n");
+		goto err_out;
+	}
+
 	desc = kzalloc((sizeof(*desc)), GFP_NOWAIT);
 	if (!desc)
 		goto err_out;
@@ -1792,6 +1802,8 @@ static void sdma_load_firmware(const struct firmware *fw, void *context)
 
 	sdma_add_scripts(sdma, addr);
 
+	sdma->fw_loaded = true;
+
 	dev_info(sdma->dev, "loaded firmware %d.%d\n",
 			header->version_major,
 			header->version_minor);