| Message ID | 20241113211614.518439-1-karprzy7@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | mfd: omap-usb-tll: check clk_prepare return code | expand |
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@gmail.com> > --- > 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); > - 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()? I think we should return the error in this case. (after unpreparing the prepared clocks and clk_put()) > + } > } > > pm_runtime_put_sync(dev);
On 19/11/2024 15:56, Andreas Kemnade wrote: > Am Tue, 19 Nov 2024 15:10:23 +0200 > schrieb Roger Quadros <rogerq@kernel.org>: > >> 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@gmail.com> >>> --- >>> 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
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); - 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); + } } pm_runtime_put_sync(dev);
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@gmail.com> --- drivers/mfd/omap-usb-tll.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)