linux-kernel - Re: [PATCH v3 00/13] mailbox: pcc: Fixes and cleanup/refactoring

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Message-ID: <20250321-elegant-ruby-bull-7d9c50@sudeepholla>
Date: Fri, 21 Mar 2025 13:57:07 +0000
From: Sudeep Holla <sudeep.holla@....com>
To: <linux-acpi@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
	Jassi Brar <jassisinghbrar@...il.com>
Cc: Sudeep Holla <sudeep.holla@....com>, Huisong Li <lihuisong@...wei.com>,
	Adam Young <admiyo@...amperecomputing.com>,
	Robbie King <robbiek@...ghtlabs.com>,
	Andi Shyti <andi.shyti@...nel.org>, <linux-i2c@...r.kernel.org>,
	Jean Delvare <jdelvare@...e.com>,
	Guenter Roeck <linux@...ck-us.net>, <linux-hwmon@...r.kernel.org>,
	"Rafael J. Wysocki" <rafael@...nel.org>
Subject: Re: [PATCH v3 00/13] mailbox: pcc: Fixes and cleanup/refactoring

On Thu, Mar 13, 2025 at 03:28:46PM +0000, Sudeep Holla wrote:
> Here is a summary of the changes in this patch series:
> 
> 1. Fix for race condition in updating of the chan_in_use flag
> 
>    Ensures correct updating of the chan_in_use flag to avoid potential race
>    conditions.
> 
> 2. Interrupt handling fix
> 
>    Ensures platform acknowledgment interrupts are always cleared to avoid
>    leaving the interrupt asserted forever.
> 
> 3. Endian conversion cleanup
> 
>    Removes unnecessary endianness conversion in the PCC mailbox driver.
> 
> 4. Memory mapping improvements
> 
>    Uses acpi_os_ioremap() instead of direct mapping methods for better ACPI
>    compatibility.
> 
> 5. Return early if the command complete register is absent
> 
>    Ensures that if no GAS (Generic Address Structure) register is available,
>    the function exits early.
> 
> 6. Refactor IRQ handler and move error handling to a separate function
> 
>    Improves readability of error handling in the PCC mailbox driver’s
>    interrupt handler.
> 
> 7. Shared memory mapping refactoring/enhancements
> 
>    Ensures the shared memory is always mapped and unmapped in the PCC
>    mailbox driver when the PCC channel is requested and release.
> 
> 8. Refactored check_and_ack() Function
> 
>    Simplifies and improves the logic for handling type4 platform notification
>    acknowledgments.
> 
> 09-13. Shared memory handling simplifications across multiple drivers
> 
>     Simplifies shared memory handling in:
>         Kunpeng HCCS driver (soc: hisilicon)
>         Apm X-Gene Slimpro I2C driver
>         X-Gene hardware monitoring driver (hwmon)
>         ACPI PCC driver
>         ACPI CPPC driver
> 
> The X-gene related changes now change the mapping attributes to align
> with ACPI specification. There are possibilities for more cleanups on
> top of these changes around how the shmem is accessed within these
> driver.
> 
> Also, my main aim is to get 1-8 merged first and target 9-13 for
> following merge window through respective tree.
> 
> Overall, the patch series focuses on improving correctness, efficiency, and
> maintainability of the PCC mailbox driver and related components by fixing
> race conditions, optimizing memory handling, simplifying shared memory
> interactions, and refactoring code for clarity.
> 
> Signed-off-by: Sudeep Holla <sudeep.holla@....com>
> ---
> Jassi,
> 
> Please take patch [1-8]/13 through the mailbox tree if and when you are
> happy with the changes.

Hi Jassi,

I2C change is also acked now. Let me know if you prefer pull request or
you prefer to take it via ACPI tree which may need you ACK.

-- 
Regards,
Sudeep