2017-12-06 13:50:34

by Andreas Platschek

Subject: [PATCH v2] dmaengine: fsl-edma: disable clks on all error paths

Previously enabled clks are only disabled if clk_prepare_enable() fails.
However, there are other error paths were the previously enabled
clocks are not disabled.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Andreas Platschek <[email protected]>
---
drivers/dma/fsl-edma.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/fsl-edma.c b/drivers/dma/fsl-edma.c
index 6775f2c74e25..9940f2f7039f 100644
--- a/drivers/dma/fsl-edma.c
+++ b/drivers/dma/fsl-edma.c
@@ -878,7 +878,7 @@ static int fsl_edma_probe(struct platform_device *pdev)
struct fsl_edma_chan *fsl_chan;
struct resource *res;
int len, chans;
- int ret, i;
+ int ret, i, j;

ret = of_property_read_u32(np, "dma-channels", &chans);
if (ret) {
@@ -904,12 +904,21 @@ static int fsl_edma_probe(struct platform_device *pdev)

res = platform_get_resource(pdev, IORESOURCE_MEM, 1 + i);
fsl_edma->muxbase[i] = devm_ioremap_resource(&pdev->dev, res);
- if (IS_ERR(fsl_edma->muxbase[i]))
+ if (IS_ERR(fsl_edma->muxbase[i])) {
+ /* disable only clks which were enabled on error */
+ for (j = i-1; j >= 0; j--)
+ clk_disable_unprepare(fsl_edma->muxclk[j]);
+
return PTR_ERR(fsl_edma->muxbase[i]);
+ }

sprintf(clkname, "dmamux%d", i);
fsl_edma->muxclk[i] = devm_clk_get(&pdev->dev, clkname);
if (IS_ERR(fsl_edma->muxclk[i])) {
+ /* disable only clks which were enabled on error */
+ for (j = i-1; j >= 0; j--)
+ clk_disable_unprepare(fsl_edma->muxclk[j]);
+
dev_err(&pdev->dev, "Missing DMAMUX block clock.\n");
return PTR_ERR(fsl_edma->muxclk[i]);
}
--
2.11.0

2017-12-13 04:50:50

by Vinod Koul

Subject: Re: [PATCH v2] dmaengine: fsl-edma: disable clks on all error paths

On Wed, Dec 06, 2017 at 02:50:23PM +0100, Andreas Platschek wrote:
> Previously enabled clks are only disabled if clk_prepare_enable() fails.
> However, there are other error paths were the previously enabled
> clocks are not disabled.
>
> Found by Linux Driver Verification project (linuxtesting.org).
>
> Signed-off-by: Andreas Platschek <[email protected]>
> ---
> drivers/dma/fsl-edma.c | 13 +++++++++++--
> 1 file changed, 11 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/dma/fsl-edma.c b/drivers/dma/fsl-edma.c
> index 6775f2c74e25..9940f2f7039f 100644
> --- a/drivers/dma/fsl-edma.c
> +++ b/drivers/dma/fsl-edma.c
> @@ -878,7 +878,7 @@ static int fsl_edma_probe(struct platform_device *pdev)
> struct fsl_edma_chan *fsl_chan;
> struct resource *res;
> int len, chans;
> - int ret, i;
> + int ret, i, j;
>
> ret = of_property_read_u32(np, "dma-channels", &chans);
> if (ret) {
> @@ -904,12 +904,21 @@ static int fsl_edma_probe(struct platform_device *pdev)
>
> res = platform_get_resource(pdev, IORESOURCE_MEM, 1 + i);
> fsl_edma->muxbase[i] = devm_ioremap_resource(&pdev->dev, res);
> - if (IS_ERR(fsl_edma->muxbase[i]))
> + if (IS_ERR(fsl_edma->muxbase[i])) {
> + /* disable only clks which were enabled on error */
> + for (j = i-1; j >= 0; j--)
^^^
space around - pls
> + clk_disable_unprepare(fsl_edma->muxclk[j]);

why not modify fsl_disable_clocks() and invoke that...?

>
> sprintf(clkname, "dmamux%d", i);
> fsl_edma->muxclk[i] = devm_clk_get(&pdev->dev, clkname);
> if (IS_ERR(fsl_edma->muxclk[i])) {
> + /* disable only clks which were enabled on error */
> + for (j = i-1; j >= 0; j--)
> + clk_disable_unprepare(fsl_edma->muxclk[j]);

ditto

--
~Vinod