From: Will Deacon <will@kernel.org>
To: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>,
linux-arm-kernel@lists.infradead.org, catalin.marinas@arm.com,
kernel-team@android.com,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
coresight@lists.linaro.org, linux-kernel@vger.kernel.org,
James Clark <james.clark@arm.com>,
Mike Leach <mike.leach@linaro.org>,
yangyicong@huawei.com, Mark Rutland <mark.rutland@arm.com>,
Sami Mujawar <sami.mujawar@arm.com>, Leo Yan <leo.yan@linaro.org>
Subject: Re: [PATCH V5 0/4] coresight: trbe: Enable ACPI based devices
Date: Mon, 28 Aug 2023 22:35:37 +0100 [thread overview]
Message-ID: <20230828213537.GA27629@willie-the-truck> (raw)
In-Reply-To: <311d0ecf-dddf-dcf5-9545-3f8a51634a9a@arm.com>
On Sun, Aug 27, 2023 at 11:11:16PM +0100, Suzuki K Poulose wrote:
> On 21/08/2023 12:28, Will Deacon wrote:
> > Hmm, the rationale behind your change to make the pdata allocation
> > per-device in ("coresight: trbe: Allocate platform data per device")
> > confuses me: with Anshuman's change to allocate the pdata using
> > devm_kzalloc(), there shouldn't be any connections for the coresight
> > core to trip over, should there?
>
> Anshuman's patch is working around the problem of "TRBE platform
> device with ACPI doesn't have a valid companion device" - this is a problem
> for the acpi_get_coresight_platform_data(). The work
> around is to move the "allocation" from coresight_get_platform_data()
> to the driver (given we don't need anything else from the ACPI except
> the IRQ). That doesn't change *how* it is allocated.
> Also please note that, the TRBE driver creates a TRBE coresight_device
> per-CPU and the platform data is shared by all of these devices, which
> the coresight core driver doesn't cope with. The other option is to
> move the releasing of these platform-data to the individual drivers,
> which is quite an invasive change. Or, make the core driver tolerate
> a NULL platform data, which is also again invasive. So the merged fix
> is correct and is still valid after this patch.
Ah, ok, so the problem with TRBE isn't anything to do with its connections,
but simply because the pdata is shared?
Will
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next prev parent reply other threads:[~2023-08-28 21:36 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-17 5:54 [PATCH V5 0/4] coresight: trbe: Enable ACPI based devices Anshuman Khandual
2023-08-17 5:54 ` [PATCH V5 1/4] arm_pmu: acpi: Refactor arm_spe_acpi_register_device() Anshuman Khandual
2023-08-17 5:54 ` [PATCH V5 2/4] arm_pmu: acpi: Add a representative platform device for TRBE Anshuman Khandual
2023-08-17 5:54 ` [PATCH V5 3/4] coresight: trbe: Add a representative coresight_platform_data " Anshuman Khandual
2023-08-17 5:54 ` [PATCH V5 4/4] coresight: trbe: Enable ACPI based TRBE devices Anshuman Khandual
2023-08-18 18:04 ` [PATCH V5 0/4] coresight: trbe: Enable ACPI based devices Will Deacon
2023-08-19 7:36 ` Suzuki K Poulose
2023-08-21 11:28 ` Will Deacon
2023-08-27 22:11 ` Suzuki K Poulose
2023-08-28 2:17 ` Anshuman Khandual
2023-08-28 21:35 ` Will Deacon [this message]
2023-08-29 8:43 ` Suzuki K Poulose
2023-08-28 2:41 ` Anshuman Khandual
2023-08-28 16:30 ` Will Deacon
2023-08-29 8:45 ` Suzuki K Poulose
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