linux-kernel - Re: [PATCH] mmc: bcm2835: Use dma_request_chan() instead dma_request_slave

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 17 Dec 2019 12:37:25 +0100
From:   Nicolas Saenz Julienne <nsaenzjulienne@...e.de>
To:     Peter Ujfalusi <peter.ujfalusi@...com>, ulf.hansson@...aro.org,
        f.fainelli@...il.com, rjui@...adcom.com, sbranden@...adcom.com
Cc:     vkoul@...nel.org, linux-mmc@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        bcm-kernel-feedback-list@...adcom.com,
        linux-rpi-kernel@...ts.infradead.org,
        linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH] mmc: bcm2835: Use dma_request_chan() instead
 dma_request_slave_channel()

Hi Peter,

On Tue, 2019-12-17 at 13:26 +0200, Peter Ujfalusi wrote:
> dma_request_slave_channel() is a wrapper on top of dma_request_chan()
> eating up the error code.
> 
> By using dma_request_chan() directly the driver can support deferred
> probing against DMA.
> 
> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@...com>
> ---
>  drivers/mmc/host/bcm2835.c | 10 +++++++++-
>  1 file changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mmc/host/bcm2835.c b/drivers/mmc/host/bcm2835.c
> index 99f61fd2a658..3821f159d36d 100644
> --- a/drivers/mmc/host/bcm2835.c
> +++ b/drivers/mmc/host/bcm2835.c
> @@ -1393,7 +1393,15 @@ static int bcm2835_probe(struct platform_device *pdev)
>  	host->dma_chan = NULL;
>  	host->dma_desc = NULL;
>  
> -	host->dma_chan_rxtx = dma_request_slave_channel(dev, "rx-tx");
> +	host->dma_chan_rxtx = dma_request_chan(dev, "rx-tx");
> +	if (IS_ERR(host->dma_chan_rxtx)) {
> +		if (PTR_ERR(host->dma_chan_rxtx) == -EPROBE_DEFER)
> +			return -EPROBE_DEFER;

I think you should 'goto err' here, as you have to free the mmc host structure
allocated earlier in the probe function.

Other than that the patch looks good to me.

Regards,
Nicolas


Download attachment "signature.asc" of type "application/pgp-signature" (489 bytes)