On 19/11/2024 15:56, Andreas Kemnade wrote:
> Am Tue, 19 Nov 2024 15:10:23 +0200
> schrieb Roger Quadros <rogerq@xxxxxxxxxx>:
>
>> Hi,
>>
>> On 13/11/2024 23:16, Karol Przybylski wrote:
>>> clk_prepare() is called in usbtll_omap_probe to fill clk array.
>>> Return code is not checked, leaving possible error condition unhandled.
>>>
>>> Added variable to hold return value from clk_prepare() and dev_dbg statement
>>> when it's not successful.
>>>
>>> Found in coverity scan, CID 1594680
>>>
>>> Signed-off-by: Karol Przybylski <karprzy7@xxxxxxxxx>
>>> ---
>>> drivers/mfd/omap-usb-tll.c | 11 +++++++----
>>> 1 file changed, 7 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/drivers/mfd/omap-usb-tll.c b/drivers/mfd/omap-usb-tll.c
>>> index 0f7fdb99c809..2e9319ee1b74 100644
>>> --- a/drivers/mfd/omap-usb-tll.c
>>> +++ b/drivers/mfd/omap-usb-tll.c
>>> @@ -202,7 +202,7 @@ static int usbtll_omap_probe(struct platform_device *pdev)
>>> struct device *dev = &pdev->dev;
>>> struct usbtll_omap *tll;
>>> void __iomem *base;
>>> - int i, nch, ver;
>>> + int i, nch, ver, err;
>>>
>>> dev_dbg(dev, "starting TI HSUSB TLL Controller\n");
>>>
>>> @@ -248,10 +248,13 @@ static int usbtll_omap_probe(struct platform_device *pdev)
>>> "usb_tll_hs_usb_ch%d_clk", i);
>>> tll->ch_clk[i] = clk_get(dev, clkname);
>>>
>>> - if (IS_ERR(tll->ch_clk[i]))
>>> + if (IS_ERR(tll->ch_clk[i])) {
>>> dev_dbg(dev, "can't get clock : %s\n", clkname);
>
> if you want dev_err() later, then why not here?
Because clk is optional. If it is not there then we should not complain.
But if it is there then it needs to be enabled successfully.
>
>>> - else
>>> - clk_prepare(tll->ch_clk[i]);
>>> + } else {
>>> + err = clk_prepare(tll->ch_clk[i]);
>>> + if (err)
>>> + dev_dbg(dev, "clock prepare error for: %s\n", clkname);
>>
>> dev_err()?
>>
> So why do you want a different return handling here? (I doubt there is
> any clock having a real prepare() involved here)
>
> As said in an earlier incarnation of this patch, the real question is
> whether having partial clocks available is a valid operating scenario.
> If yes, then the error should be ignored. If no, then bailing out early
> is a good idea.
In the DT binding, clocks is optional. So if it doesn't exist it is not
an error condition.
>
> clk_prepare() errors are catched by failing clk_enable() later,
> ch_clk[i] is checked later, too.
>
>> I think we should return the error in this case.
>> (after unpreparing the prepared clocks and clk_put())
>>
> and pm_runtime_put_sync(dev)
>
> Regards,
> Andreas
--
cheers,
-roger
