linux-kernel - Re: [PATCH v14 05/12] dmaengine: dma: imx-sdma: add fw_loaded and is_ram

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Message-ID: <17cadf46f4a0f9771fdde1c9aba9ffecb20efc9f.camel@pengutronix.de>
Date:   Fri, 09 Jul 2021 11:24:48 +0200
From:   Lucas Stach <l.stach@...gutronix.de>
To:     Robin Gong <yibin.gong@....com>, vkoul@...nel.org,
        mark.rutland@....com, broonie@...nel.org, robh+dt@...nel.org,
        catalin.marinas@....com, will.deacon@....com, shawnguo@...nel.org,
        festevam@...il.com, s.hauer@...gutronix.de,
        martin.fuzzey@...wbird.group, u.kleine-koenig@...gutronix.de,
        dan.j.williams@...el.com, matthias.schiffer@...tq-group.com,
        frieder.schrempf@...tron.de, m.felsch@...gutronix.de,
        xiaoning.wang@....com
Cc:     devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-spi@...r.kernel.org, linux-imx@....com,
        kernel@...gutronix.de, dmaengine@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH v14 05/12] dmaengine: dma: imx-sdma: add fw_loaded and
 is_ram_script

Am Mittwoch, dem 07.04.2021 um 23:30 +0800 schrieb Robin Gong:
> 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@....com>
> Acked-by: Vinod Koul <vkoul@...nel.org>
> ---
>  drivers/dma/imx-sdma.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
> index 1c636d2..78dcfe2 100644
> --- a/drivers/dma/imx-sdma.c
> +++ b/drivers/dma/imx-sdma.c
> @@ -381,6 +381,7 @@ 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)
> @@ -444,6 +445,7 @@ 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,
> @@ -899,6 +901,7 @@ 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:
> @@ -913,6 +916,7 @@ 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;
> @@ -1309,6 +1313,11 @@ 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;
> @@ -1559,6 +1568,8 @@ static int sdma_config_write(struct dma_chan *chan,
>  {
>  	struct sdma_channel *sdmac = to_sdma_chan(chan);
>  
> +	sdmac->is_ram_script = false;
> +
While it's working correctly, I find it confusing to have this
initialization at this point in the code. Please fold this into
sdma_get_pc(), where it gets changed as needed.

Other than this small issue, this patch is:
Reviewed-by: Lucas Stach <l.stach@...gutronix.de>

>  	if (direction == DMA_DEV_TO_MEM) {
>  		sdmac->per_address = dmaengine_cfg->src_addr;
>  		sdmac->watermark_level = dmaengine_cfg->src_maxburst *
> @@ -1738,6 +1749,8 @@ 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);