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From: Gabriele Mazzotta <gabriele.mzt@gmail.com>
Cc: jic23@kernel.org, knaack.h@gmx.de, lars@metafoo.de,
	pmeerw@pmeerw.net, marxin.liska@gmail.com, marex@denx.de,
	rui.zhang@intel.com, linux-kernel@vger.kernel.org,
	linux-iio@vger.kernel.org
Subject: Re: [PATCH] iio: acpi: Add ACPI0008 Ambient Light Sensor
Date: Fri, 01 May 2015 18:12:14 +0200	[thread overview]
Message-ID: <10033848.82LkUmdQLq@xps13> (raw)
In-Reply-To: <1430306845-7117-1-git-send-email-gabriele.mzt@gmail.com>

Hi,

probably this is not completely related to this driver, but I
noticed something while testing it.

When I load acpi-als, /sys/bus/iio/devices/iio:device0/buffer/enable
is 0. If I try to set it to 1, I get the following error:
"Buffer not started: buffer parameter update failed (-22)"

After I got the error, I can successfully toggle "enable".

What I found is that the first time iio_request_update_kfifo() is
called, __iio_allocate_kfifo() gets called. Since bytes_per_datum
is 0 (as set iio_compute_scan_bytes()), it returns -EINVAL and so
does iio_request_update_kfifo(), causing the error above.

Subsequent calls of iio_request_update_kfifo() will return 0 as
update_needed is false, so "enable" can be toggled with no errors.

Isn't there something wrong here?

Regards,
Gabriele

WARNING: multiple messages have this Message-ID (diff)
From: Gabriele Mazzotta <gabriele.mzt@gmail.com>
To: unlisted-recipients:; (no To-header on input)
Cc: jic23@kernel.org, knaack.h@gmx.de, lars@metafoo.de,
	pmeerw@pmeerw.net, marxin.liska@gmail.com, marex@denx.de,
	rui.zhang@intel.com, linux-kernel@vger.kernel.org,
	linux-iio@vger.kernel.org
Subject: Re: [PATCH] iio: acpi: Add ACPI0008 Ambient Light Sensor
Date: Fri, 01 May 2015 18:12:14 +0200	[thread overview]
Message-ID: <10033848.82LkUmdQLq@xps13> (raw)
In-Reply-To: <1430306845-7117-1-git-send-email-gabriele.mzt@gmail.com>

Hi,

probably this is not completely related to this driver, but I
noticed something while testing it.

When I load acpi-als, /sys/bus/iio/devices/iio:device0/buffer/enable
is 0. If I try to set it to 1, I get the following error:
"Buffer not started: buffer parameter update failed (-22)"

After I got the error, I can successfully toggle "enable".

What I found is that the first time iio_request_update_kfifo() is
called, __iio_allocate_kfifo() gets called. Since bytes_per_datum
is 0 (as set iio_compute_scan_bytes()), it returns -EINVAL and so
does iio_request_update_kfifo(), causing the error above.

Subsequent calls of iio_request_update_kfifo() will return 0 as
update_needed is false, so "enable" can be toggled with no errors.

Isn't there something wrong here?

Regards,
Gabriele

  parent reply	other threads:[~2015-05-01 16:12 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-04-29 11:27 [PATCH] iio: acpi: Add ACPI0008 Ambient Light Sensor Gabriele Mazzotta
2015-04-29 11:51 ` Gabriele Mazzotta
2015-04-29 14:33   ` Marek Vasut
2015-04-29 15:36     ` Gabriele Mazzotta
2015-04-30  9:44       ` Marek Vasut
2015-04-30 11:27         ` Gabriele Mazzotta
2015-04-30 11:30           ` Marek Vasut
2015-04-30 12:24 ` Daniel Baluta
2015-04-30 19:14   ` Gabriele Mazzotta
2015-04-30 20:33 ` Paul Bolle
2015-04-30 20:58   ` Marek Vasut
2015-05-01 16:12 ` Gabriele Mazzotta [this message]
2015-05-01 16:12   ` Gabriele Mazzotta
2015-05-02 11:22   ` Jonathan Cameron
2015-05-02 11:25 ` Jonathan Cameron

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