[PATCH V10 2/7] soc: qcom: dcc:Add driver support for Data Capture and Compare unit(DCC)

Bjorn Andersson andersson at kernel.org
Thu Sep 15 08:15:40 PDT 2022


On Thu, Sep 15, 2022 at 07:48:42PM +0530, Souradeep Chowdhury wrote:
> The DCC is a DMA Engine designed to capture and store data
> during system crash or software triggers. The DCC operates
> based on user inputs via the debugfs interface. The user gives
> addresses as inputs and these addresses are stored in the
> dcc sram. In case of a system crash or a manual software
> trigger by the user through the debugfs interface,
> the dcc captures and stores the values at these addresses.
> This patch contains the driver which has all the methods
> pertaining to the debugfs interface, auxiliary functions to
> support all the four fundamental operations of dcc namely
> read, write, read/modify/write and loop. The probe method
> here instantiates all the resources necessary for dcc to
> operate mainly the dedicated dcc sram where it stores the
> values. The DCC driver can be used for debugging purposes
> without going for a reboot since it can perform software
> triggers as well based on user inputs.
> 
> Also added the documentation for debugfs entries and explained
> the functionalities of each debugfs file that has been created
> for dcc.
> 
> The following is the justification of using debugfs interface
> over the other alternatives like sysfs/ioctls
> 
> i) As can be seen from the debugfs attribute descriptions,
> some of the debugfs attribute files here contains multiple
> arguments which needs to be accepted from the user. This goes
> against the design style of sysfs.
> 
> ii) The user input patterns have been made simple and convenient
> in this case with the use of debugfs interface as user doesn't
> need to shuffle between different files to execute one instruction
> as was the case on using other alternatives.
> 
> Signed-off-by: Souradeep Chowdhury <quic_schowdhu at quicinc.com>

Thanks for the respin Souradeep. checkpatch --strict still gives me 5
warnings and 49 checks, please fix 48 of those checks.


Please also add a space after "dcc:" in $subject.

Regards,
Bjorn



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