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bh=UHzlhV0Yxj6WUPZw2k/60+gIXMZg6++itYA8ktT0Kn4=; b=rRunNt5KKSy/A0O+HsKtYx94+JYyuY4NP2fr5I29MvAypNL9I+MK3H+KsrLFJl9TpG UnDRg5eEuf52tHoM9E1d9O7nTCyCafREOsrcXWGXRlHwgXNrBXtBb9AasETcOegJYMa0 oVQIsYruIK56HhZnYal4IzDpGLXubpdvWrhq9EG6Hd5mbOAAZ2kI2Pqn/J9jzSMqFf8R fFw0q4HuKSB7mIe6tUOP8UQJGXR17u8xPzxTFeFu6vlpNDLD6sVANrR/0leRJoOknHTK 4cUvq5OROPmwrkrOPjT4XlYNx3EsmLMfn1XW+/WTN/pUGcLZ58T4+5DyIw2sH5vKycPx xNtA== X-Gm-Message-State: AOAM532bvqpY90dO+gNT3QiwmiWbnUxT7yyDQASpjrubtzjxSUPlAZWV UnXYYjK+3upM7jwQeW5uZUZO+G2NxuxOoZspl48= X-Google-Smtp-Source: ABdhPJzWdOa/xWuu7O3Ro6MUSWD6EmK/LsoQxUscq2mPnYeCAHakF5ueX+2C2JW+iJY92iJY1GxL2s1gowdfCaHJWWg= X-Received: by 2002:a17:902:ceca:b029:112:b67b:fe4f with SMTP id d10-20020a170902cecab0290112b67bfe4fmr8398508plg.32.1623141198940; Tue, 08 Jun 2021 01:33:18 -0700 (PDT) MIME-Version: 1.0 References: <20210607113715.110292-1-chi962464zy@163.com> <20210608092337.00006b11@163.com> In-Reply-To: <20210608092337.00006b11@163.com> From: Alexandru Ardelean Date: Tue, 8 Jun 2021 11:33:07 +0300 Message-ID: Subject: Re: [PATCH] iio: imu: inv_mpu6050:Adding judgment dev which is maybe a void pointer To: Guoqing Chi Cc: Jonathan Cameron , linux-iio , chiguoqing@yulong.com, Randy Dunlap Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org On Tue, Jun 8, 2021 at 4:23 AM Guoqing Chi wrote: > > On Mon, 7 Jun 2021 16:20:06 +0300 > Alexandru Ardelean wrote: > > > On Mon, Jun 7, 2021 at 2:39 PM Guoqing Chi > > wrote: > > > > > > From: Guoqing Chi > > > > > > ff40: 00000000 95fffa74 00000000 e07b2198 00000000 00000007 > > > 81391000 e07b2198 ff60: 00000007 81391000 81267834 81391000 > > > 0000015a 81200f00 00000006 00000006 ff80: 00000000 81200514 > > > 00000000 80bfbd88 00000000 00000000 00000000 00000000 ffa0: > > > 00000000 80bfbd90 00000000 801010e8 00000000 00000000 00000000 > > > 00000000 ffc0: 00000000 00000000 00000000 00000000 00000000 > > > 00000000 00000000 00000000 ffe0: 00000000 00000000 00000000 > > > 00000000 00000013 00000000 00000000 00000000 [<808f3228>] > > > (inv_mpu_i2c_aux_setup) from [<808f1c18>] > > > (inv_mpu_core_probe+0x638/0x878) [<808f1c18>] (inv_mpu_core_probe) > > > from [<808f3100>] (inv_mpu_probe+0xe4/0x1f0) [<808f3100>] > > > (inv_mpu_probe) from [<80801c88>] (i2c_device_probe+0x238/0x26c) > > > [<80801c88>] (i2c_device_probe) from [<8063520c>] > > > (really_probe+0x218/0x348) [<8063520c>] (really_probe) from > > > [<806354b4>] (driver_probe_device+0x60/0x164) [<806354b4>] > > > (driver_probe_device) from [<80635760>] > > > (device_driver_attach+0x58/0x60) [<80635760>] > > > (device_driver_attach) from [<806357e8>] > > > (__driver_attach+0x80/0xbc) [<806357e8>] (__driver_attach) from > > > [<80633560>] (bus_for_each_dev+0x74/0xb4) [<80633560>] > > > (bus_for_each_dev) from [<80634548>] (bus_add_driver+0x160/0x1e4) > > > [<80634548>] (bus_add_driver) from [<80636018>] > > > (driver_register+0x7c/0x114) [<80636018>] (driver_register) from > > > [<80801644>] (i2c_register_driver+0x3c/0x80) [<80801644>] > > > (i2c_register_driver) from [<8010277c>] > > > (do_one_initcall+0x54/0x1b8) [<8010277c>] (do_one_initcall) from > > > [<81200f00>] (kernel_init_freeable+0x144/0x1e0) [<81200f00>] > > > (kernel_init_freeable) from [<80bfbd90>] (kernel_init+0x8/0x10c) > > > [<80bfbd90>] (kernel_init) from [<801010e8>] > > > (ret_from_fork+0x14/0x2c) > > > > > > If we do not use aux or forget config child node at dts,it will be > > > in dump. > > > > > > Signed-off-by: Guoqing Chi > > > --- > > > drivers/iio/imu/inv_mpu6050/inv_mpu_i2c.c | 5 ++++- > > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > > > diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_i2c.c > > > b/drivers/iio/imu/inv_mpu6050/inv_mpu_i2c.c index > > > 95f16951c8f4..b0f45042a25f 100644 --- > > > a/drivers/iio/imu/inv_mpu6050/inv_mpu_i2c.c +++ > > > b/drivers/iio/imu/inv_mpu6050/inv_mpu_i2c.c @@ -77,11 +77,14 @@ > > > static int inv_mpu_i2c_aux_setup(struct iio_dev *indio_dev) } > > > > > > /* enable i2c bypass when using i2c auxiliary bus */ > > > - if (inv_mpu_i2c_aux_bus(dev)) { > > > + if (dev != NULL && inv_mpu_i2c_aux_bus(dev)) { > > > > One point is that this solves the issue for the I2C variant, but > > doesn't seem to handle the SPI variant of the driver/device. > > So, maybe this should be checked for NULL in inv_mpu_core_probe(). > > > > But, the 'dev' reference comes from this assignment 'struct device > > *dev = indio_dev->dev.parent;', which looks impossible given that the > > IIO device-object was created with devm_iio_device_alloc(). > > So, 'indio_dev->dev.parent' can't be NULL, as far as I can tell. > > > > On what version of the kernel has this been seen? > > Hi Alexandru: > In kernel 5.4.70_2.3.0,and find the devm_iio_device_alloc() differ from > new version,The problem occurs apply the newest mpu6050 driver to > kernel 5.4.70,i will check it. Sometime in kernel 5.8, this commit was added: [1] https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git/commit/?h=78289b4a58b58e9a8a76ef43ffbaf04a097e33c6 Then a lot of drivers got their manual parent assignment cleaned up. If you backport a driver from the latest kernel, without patch [1], you risk getting crashes/invalid behavior. > > Thanks. > > > > > > ret = regmap_write(st->map, st->reg->int_pin_cfg, > > > st->irq_mask | > > > INV_MPU6050_BIT_BYPASS_EN); if (ret) > > > return ret; > > > + } else { > > > + dev_err(&indio_dev->dev, "Failed to enable i2c > > > bypass.\n"); > > > + return -EFAULT; > > > } > > > > > > return 0; > > > -- > > > 2.17.1 > > > >