From: Thierry Reding <thierry.reding@gmail.com>
To: Dmitry Osipenko <digetx@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>,
Laxman Dewangan <ldewangan@nvidia.com>,
Wolfram Sang <wsa@the-dreams.de>,
linux-i2c@vger.kernel.org, linux-tegra@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v1 1/3] i2c: tegra: Support atomic transfers
Date: Fri, 13 Dec 2019 16:12:08 +0100 [thread overview]
Message-ID: <20191213151208.GC222809@ulmo> (raw)
In-Reply-To: <20191212233428.14648-2-digetx@gmail.com>
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On Fri, Dec 13, 2019 at 02:34:26AM +0300, Dmitry Osipenko wrote:
> System shutdown may happen with interrupts being disabled and in this case
> I2C core rejects transfers if atomic transfer isn't supported by driver.
>
> There were several occurrences where I found my Nexus 7 completely
> discharged despite of being turned off and then one day I spotted this in
> the log:
>
> reboot: Power down
> ------------[ cut here ]------------
> WARNING: CPU: 0 PID: 1 at drivers/i2c/i2c-core.h:40 i2c_transfer+0x95/0x9c
> No atomic I2C transfer handler for 'i2c-1'
> Modules linked in: tegra30_devfreq
> CPU: 0 PID: 1 Comm: systemd-shutdow Not tainted 5.4.0-next-20191202-00120-gf7ecd80fb803-dirty #3195
> Hardware name: NVIDIA Tegra SoC (Flattened Device Tree)
> [<c010e4b5>] (unwind_backtrace) from [<c010a0fd>] (show_stack+0x11/0x14)
> [<c010a0fd>] (show_stack) from [<c09995e5>] (dump_stack+0x85/0x94)
> [<c09995e5>] (dump_stack) from [<c011f3d1>] (__warn+0xc1/0xc4)
> [<c011f3d1>] (__warn) from [<c011f691>] (warn_slowpath_fmt+0x61/0x78)
> [<c011f691>] (warn_slowpath_fmt) from [<c069a8dd>] (i2c_transfer+0x95/0x9c)
> [<c069a8dd>] (i2c_transfer) from [<c05667f1>] (regmap_i2c_read+0x4d/0x6c)
> [<c05667f1>] (regmap_i2c_read) from [<c0563601>] (_regmap_raw_read+0x99/0x1cc)
> [<c0563601>] (_regmap_raw_read) from [<c0563757>] (_regmap_bus_read+0x23/0x38)
> [<c0563757>] (_regmap_bus_read) from [<c056293d>] (_regmap_read+0x3d/0xfc)
> [<c056293d>] (_regmap_read) from [<c0562d3b>] (_regmap_update_bits+0x87/0xc4)
> [<c0562d3b>] (_regmap_update_bits) from [<c0563add>] (regmap_update_bits_base+0x39/0x50)
> [<c0563add>] (regmap_update_bits_base) from [<c056fd39>] (max77620_pm_power_off+0x29/0x2c)
> [<c056fd39>] (max77620_pm_power_off) from [<c013bbdd>] (__do_sys_reboot+0xe9/0x170)
> [<c013bbdd>] (__do_sys_reboot) from [<c0101001>] (ret_fast_syscall+0x1/0x28)
> Exception stack(0xde907fa8 to 0xde907ff0)
> 7fa0: 00000000 00000000 fee1dead 28121969 4321fedc 00000000
> 7fc0: 00000000 00000000 00000000 00000058 00000000 00000000 00000000 00000000
> 7fe0: 0045adf0 bed9abb8 004444a0 b6c666d0
> ---[ end trace bdd18f87595b1a5e ]---
>
> The atomic transferring is implemented by enforcing PIO mode for the
> transfer and by polling interrupt status until transfer is completed or
> failed.
>
> Now system shuts down properly every time.
>
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
> drivers/i2c/busses/i2c-tegra.c | 95 +++++++++++++++++++++++++++++++---
> 1 file changed, 88 insertions(+), 7 deletions(-)
I ran this on the test farm and the results are all green, so:
Tested-by: Thierry Reding <treding@nvidia.com>
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next prev parent reply other threads:[~2019-12-13 15:12 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-12 23:34 [PATCH v1 0/3] Tegra I2C: Support atomic transfers and correct suspend/resume Dmitry Osipenko
2019-12-12 23:34 ` [PATCH v1 1/3] i2c: tegra: Support atomic transfers Dmitry Osipenko
2019-12-13 14:36 ` Dmitry Osipenko
2019-12-13 15:12 ` Thierry Reding [this message]
2019-12-13 15:15 ` Dmitry Osipenko
2019-12-13 15:20 ` Thierry Reding
2019-12-13 15:25 ` Dmitry Osipenko
2019-12-12 23:34 ` [PATCH v1 2/3] i2c: tegra: Rename I2C_PIO_MODE_MAX_LEN to I2C_PIO_MODE_PREFERRED_LEN Dmitry Osipenko
2019-12-13 15:12 ` Thierry Reding
2019-12-12 23:34 ` [PATCH v1 3/3] i2c: tegra: Fix suspending in active runtime PM state Dmitry Osipenko
2019-12-12 23:43 ` Dmitry Osipenko
2019-12-13 13:47 ` Thierry Reding
2019-12-13 14:04 ` Dmitry Osipenko
2019-12-13 18:01 ` Dmitry Osipenko
2019-12-19 22:58 ` Dmitry Osipenko
2019-12-27 13:47 ` Dmitry Osipenko
2019-12-13 14:29 ` Dmitry Osipenko
2019-12-13 14:55 ` Dmitry Osipenko
2019-12-27 13:55 ` Dmitry Osipenko
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