On Thu, 31 Aug 2017, Alexandre Belloni wrote: > Hi, > > On 31/08/2017 at 21:08:10 +0200, Christophe JAILLET wrote: > > Le 31/08/2017 à 12:38, Mark Brown a écrit : > > > On Thu, Aug 31, 2017 at 12:31:33PM +0200, Takashi Iwai wrote: > > > > > > > This is again a typical problem by such a trivial fix patch: the code > > > > looks as if it were trivial and correct, buried in a patch series that > > > > easily leads to the oversight by the maintainer's review. > > > Right, plus the amount of context that diff shows you. > > > > > Hi, > > > > My proposed patch was initially triggered using coccinelle, as you must have > > guessed. > > > > In fact, I was surprised by the initial commit. > > I don't have any strong opinion if testing the return value of > > 'clk_prepare_enable()' is relevant or not, but I was surprised that the > > error handling path had not been updated at the same time. > > > > So, before posting my patch, I have searched a bit in git history and it > > gave: > > > > git shortlog --author="Arvind Yadav" | grep clk_prepare > > ata: sata_rcar: Handle return value of clk_prepare_enable > > hwrng: omap3-rom - Handle return value of clk_prepare_enable > > crypto: img-hash - Handle return value of clk_prepare_enable > > dmaengine: DW DMAC: Handle return value of clk_prepare_enable > > gpio: davinci: Handle return value of clk_prepare_enable > > cpufreq: kirkwood-cpufreq:- Handle return value of > > clk_prepare_enable() > > dmaengine: imx-sdma: Handle return value of clk_prepare_enable > > Input: s3c2410_ts - handle return value of clk_prepare_enable > > iio: adc: xilinx: Handle return value of clk_prepare_enable > > iio:adc:lpc32xx Handle return value of clk_prepare_enable > > memory: ti-aemif: Handle return value of clk_prepare_enable > > spi: davinci: Handle return value of clk_prepare_enable > > [media] tc358743: Handle return value of clk_prepare_enable > > mtd: nand: orion: Handle return value of clk_prepare_enable > > iio: Aspeed ADC - Handle return value of clk_prepare_enable > > PM / devfreq: exynos-nocp: Handle return value of clk_prepare_enable > > PM / devfreq: exynos-ppmu: Handle return value of clk_prepare_enable > > usb: host: ehci-exynos: Handle return value of clk_prepare_enable > > usb: mtu3: Handle return value of clk_prepare_enable > > usb: mtu3: Handle return value of clk_prepare_enable > > video: fbdev: pxafb: Handle return value of clk_prepare_enable > > usb: gadget: mv_udc: Handle return value of clk_prepare_enable. > > usb: dwc3: exynos: Handle return value of clk_prepare_enable > > i2c: at91: Handle return value of clk_prepare_enable > > i2c: emev2: Handle return value of clk_prepare_enable > > usb: host: ohci-pxa27x: Handle return value of clk_prepare_enable > > thermal: imx: Handle return value of clk_prepare_enable > > thermal: hisilicon: Handle return value of clk_prepare_enable > > PCI: rockchip: Check for clk_prepare_enable() errors during resume > > watchdog: meson: Handle return value of clk_prepare_enable > > watchdog: davinci: Handle return value of clk_prepare_enable > > mfd: tc6393xb: Handle return value of clk_prepare_enable > > ASoC: samsung: s3c2412: Handle return value of clk_prepare_enable. > > ASoC: samsung: s3c24xx: Handle return value of clk_prepare_enable. > > ASoC: samsung: pcm: Handle return value of clk_prepare_enable. > > ASoC: samsung: i2s: Handle return value of clk_prepare_enable. > > ASoC: samsung: spdif: Handle return value of clk_prepare_enable. > > ASoC: mxs-saif: Handle return value of clk_prepare_enable/clk_prepare. > > ASoC: jz4740: Handle return value of clk_prepare_enable. > > ASoC: sun4i-spdif: Handle return value of clk_prepare_enable. > > ASoC: atmel: ac97c: Handle return value of clk_prepare_enable. > > gpio: mb86s7x: Handle return value of clk_prepare_enable. > > memory: mtk-smi: Handle return value of clk_prepare_enable > > mmc: sdhci-st: Handle return value of clk_prepare_enable > > mmc: wmt-sdmmc: Handle return value of clk_prepare_enable > > mmc: mxcmmc: Handle return value of clk_prepare_enable > > dmaengine: at_xdmac: Handle return value of clk_prepare_enable. > > mtd: nand: denali: Handle return value of clk_prepare_enable. > > mtd: oxnas_nand: Handle clk_prepare_enable/clk_disable_unprepare. > > mtd: nand: lpc32xx_slc: Handle return value of clk_prepare_enable. > > mtd: nand: lpc32xx_mlc: Handle return value of clk_prepare_enable. > > mtd: st_spi_fsm: Handle clk_prepare_enable/clk_disable_unprepare. > > > > Some of these are after a devm_clk_get(), which does not require a > > modification in the error handling path (at least according to the one I've > > looked at) > > > > Some don't have any [devm_]clk_get() in the same function, and were not > > investigated further. > > > > But several also had the same construction as the one reported in this > > thread, and needed, IMHO, an update of the error handling path to call > > through clk_put(). > > > > > > It was "too" surprising to me to have "all" these "obviously" incomplete > > patches merged. > > I thought that I had missed something obvious and decided to propose one fix > > to see the reaction (and didn't expected all your replies!) > > > > You didn't miss anything, that's exactly what I am complaining about > some of the patches were OK, some aren't and all the real work is left > to the maintainer. The commit message is also a bit strange: clk_prepare_enable() and clk_prepare() can fail here and we must check its return value. When someone in the future is tring to understand whether or nor calls to clk_prepare_enable can fail, it would be misleading to have "can fail" and "we must check" in the history of a context where failure is not possible. julia > > > So now, I think we should go through the commits above to either revert the > > commit and remove the test (and document why it is not needed) or fix the > > error handling path accordingly, even if one could know that it cant' > > happen. > > I think you should go ahead and fix those now... > > -- > Alexandre Belloni, Free Electrons > Embedded Linux and Kernel engineering > http://free-electrons.com > -- > To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html >
