Hi chunhui,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on drm/drm-next] [also build test WARNING on v4.17-rc4 next-20180507] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Bibby-Hsieh/drm-mediatek-support-hd... base: git://people.freedesktop.org/~airlied/linux.git drm-next config: arm-allyesconfig (attached as .config) compiler: arm-linux-gnueabi-gcc (Debian 7.2.0-11) 7.2.0 reproduce: wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # save the attached .config to linux build tree make.cross ARCH=arm
Note: it may well be a FALSE warning. FWIW you are at least aware of it now. http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings
All warnings (new ones prefixed by >>):
drivers/gpu//drm/mediatek/mtk_dpi.c: In function 'mtk_dpi_power_on':
drivers/gpu//drm/mediatek/mtk_dpi.c:444:9: warning: 'ret' may be used uninitialized in this function [-Wmaybe-uninitialized]
return ret; ^~~
vim +/ret +444 drivers/gpu//drm/mediatek/mtk_dpi.c
9e629c17 Jie Qiu 2016-01-04 405 9e629c17 Jie Qiu 2016-01-04 406 static int mtk_dpi_power_on(struct mtk_dpi *dpi, enum mtk_dpi_power_ctl pctl) 9e629c17 Jie Qiu 2016-01-04 407 { 9e629c17 Jie Qiu 2016-01-04 408 int ret; 9e629c17 Jie Qiu 2016-01-04 409 51df75e5 chunhui dai 2018-05-08 410 if (++dpi->refcount != 1) 51df75e5 chunhui dai 2018-05-08 411 return 0; 51df75e5 chunhui dai 2018-05-08 412 9e629c17 Jie Qiu 2016-01-04 413 dpi->power_ctl |= pctl; 9e629c17 Jie Qiu 2016-01-04 414 9e629c17 Jie Qiu 2016-01-04 415 if (!(dpi->power_ctl & DPI_POWER_START) && 9e629c17 Jie Qiu 2016-01-04 416 !(dpi->power_ctl & DPI_POWER_ENABLE)) 51df75e5 chunhui dai 2018-05-08 417 goto err_refcount; 9e629c17 Jie Qiu 2016-01-04 418 9e629c17 Jie Qiu 2016-01-04 419 if (dpi->power_sta) 51df75e5 chunhui dai 2018-05-08 420 goto err_refcount; 9e629c17 Jie Qiu 2016-01-04 421 9e629c17 Jie Qiu 2016-01-04 422 ret = clk_prepare_enable(dpi->engine_clk); 9e629c17 Jie Qiu 2016-01-04 423 if (ret) { 9e629c17 Jie Qiu 2016-01-04 424 dev_err(dpi->dev, "Failed to enable engine clock: %d\n", ret); 9e629c17 Jie Qiu 2016-01-04 425 goto err_eng; 9e629c17 Jie Qiu 2016-01-04 426 } 9e629c17 Jie Qiu 2016-01-04 427 9e629c17 Jie Qiu 2016-01-04 428 ret = clk_prepare_enable(dpi->pixel_clk); 9e629c17 Jie Qiu 2016-01-04 429 if (ret) { 9e629c17 Jie Qiu 2016-01-04 430 dev_err(dpi->dev, "Failed to enable pixel clock: %d\n", ret); 9e629c17 Jie Qiu 2016-01-04 431 goto err_pixel; 9e629c17 Jie Qiu 2016-01-04 432 } 9e629c17 Jie Qiu 2016-01-04 433 9e629c17 Jie Qiu 2016-01-04 434 mtk_dpi_enable(dpi); 9e629c17 Jie Qiu 2016-01-04 435 dpi->power_sta = true; 9e629c17 Jie Qiu 2016-01-04 436 return 0; 9e629c17 Jie Qiu 2016-01-04 437 9e629c17 Jie Qiu 2016-01-04 438 err_pixel: 9e629c17 Jie Qiu 2016-01-04 439 clk_disable_unprepare(dpi->engine_clk); 9e629c17 Jie Qiu 2016-01-04 440 err_eng: 9e629c17 Jie Qiu 2016-01-04 441 dpi->power_ctl &= ~pctl; 51df75e5 chunhui dai 2018-05-08 442 err_refcount: 51df75e5 chunhui dai 2018-05-08 443 dpi->refcount--; 9e629c17 Jie Qiu 2016-01-04 @444 return ret; 9e629c17 Jie Qiu 2016-01-04 445 } 9e629c17 Jie Qiu 2016-01-04 446
:::::: The code at line 444 was first introduced by commit :::::: 9e629c17aa8d7a75b8c1d99ed42892cd8ba7cdc4 drm/mediatek: Add DPI sub driver
:::::: TO: Jie Qiu jie.qiu@mediatek.com :::::: CC: Philipp Zabel p.zabel@pengutronix.de
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