openkylin
/
linux
mirror of https://gitee.com/openkylin/linux.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

hwrng: omap - Fix assumption that runtime_get_sync will always succeed 

pm_runtime_get_sync does return a error value that must be checked for
error conditions, else, due to various reasons, the device maynot be
enabled and the system will crash due to lack of clock to the hardware
module.

Before:
12.562784] [00000000] *pgd=fe193835
12.562792] Internal error: : 1406 [#1] SMP ARM
[...]
12.562864] CPU: 1 PID: 241 Comm: modprobe Not tainted 4.7.0-rc4-next-20160624 #2
12.562867] Hardware name: Generic DRA74X (Flattened Device Tree)
12.562872] task: ed51f140 ti: ed44c000 task.ti: ed44c000
12.562886] PC is at omap4_rng_init+0x20/0x84 [omap_rng]
12.562899] LR is at set_current_rng+0xc0/0x154 [rng_core]
[...]

After the proper checks:
[   94.366705] omap_rng 48090000.rng: _od_fail_runtime_resume: FIXME:
missing hwmod/omap_dev info
[   94.375767] omap_rng 48090000.rng: Failed to runtime_get device -19
[   94.382351] omap_rng 48090000.rng: initialization failed.

Fixes: 665d92fa85 ("hwrng: OMAP: convert to use runtime PM")
Cc: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Nishanth Menon 2016-06-24 11:50:39 -05:00 committed by Herbert Xu
parent 90ab5a814a
commit 61dc0a446e
1 changed files with 14 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
drivers/char/hw_random/omap-rng.c
View File

@ -384,7 +384,12 @@ static int omap_rng_probe(struct platform_device *pdev)
}
pm_runtime_enable(&pdev->dev);
pm_runtime_get_sync(&pdev->dev);
ret = pm_runtime_get_sync(&pdev->dev);
if (ret) {
dev_err(&pdev->dev, "Failed to runtime_get device: %d\n", ret);
pm_runtime_put_noidle(&pdev->dev);
goto err_ioremap;
}
ret = (dev->of_node) ? of_get_omap_rng_device_details(priv, pdev) :
get_omap_rng_device_details(priv);
@ -435,8 +440,15 @@ static int __maybe_unused omap_rng_suspend(struct device *dev)
static int __maybe_unused omap_rng_resume(struct device *dev)
{
struct omap_rng_dev *priv = dev_get_drvdata(dev);
int ret;
ret = pm_runtime_get_sync(dev);
if (ret) {
dev_err(dev, "Failed to runtime_get device: %d\n", ret);
pm_runtime_put_noidle(dev);
return ret;
}
pm_runtime_get_sync(dev);
priv->pdata->init(priv);
return 0;