From: Jolly Shah <JOLLYS@xilinx.com>
To: Greg KH <gregkh@linuxfoundation.org>
Cc: "ard.biesheuvel@linaro.org" <ard.biesheuvel@linaro.org>,
"mingo@kernel.org" <mingo@kernel.org>,
"matt@codeblueprint.co.uk" <matt@codeblueprint.co.uk>,
"sudeep.holla@arm.com" <sudeep.holla@arm.com>,
"hkallweit1@gmail.com" <hkallweit1@gmail.com>,
"keescook@chromium.org" <keescook@chromium.org>,
"dmitry.torokhov@gmail.com" <dmitry.torokhov@gmail.com>,
"michal.simek@xilinx.com" <michal.simek@xilinx.com>,
"robh+dt@kernel.org" <robh+dt@kernel.org>,
"mark.rutland@arm.com" <mark.rutland@arm.com>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
Rajan Vaja <RAJANV@xilinx.com>
Subject: RE: [PATCH v2 4/4] drivers: firmware: xilinx: Add debugfs interface
Date: Wed, 24 Jan 2018 23:33:50 +0000 [thread overview]
Message-ID: <DM2PR0201MB0767AE5B7E37276806A3FED4B8E20@DM2PR0201MB0767.namprd02.prod.outlook.com> (raw)
In-Reply-To: <20180123084103.GC21463@kroah.com>
Thanks for review Greg,
> -----Original Message-----
> From: Greg KH [mailto:gregkh@linuxfoundation.org]
> Sent: Tuesday, January 23, 2018 12:41 AM
> To: Jolly Shah <JOLLYS@xilinx.com>
> Cc: ard.biesheuvel@linaro.org; mingo@kernel.org; matt@codeblueprint.co.uk;
> sudeep.holla@arm.com; hkallweit1@gmail.com; keescook@chromium.org;
> dmitry.torokhov@gmail.com; michal.simek@xilinx.com; robh+dt@kernel.org;
> mark.rutland@arm.com; linux-arm-kernel@lists.infradead.org; linux-
> kernel@vger.kernel.org; devicetree@vger.kernel.org; Rajan Vaja
> <RAJANV@xilinx.com>; Jolly Shah <JOLLYS@xilinx.com>
> Subject: Re: [PATCH v2 4/4] drivers: firmware: xilinx: Add debugfs interface
>
> On Wed, Jan 17, 2018 at 12:20:34PM -0800, Jolly Shah wrote:
> > +/* Setup debugfs fops */
> > +static const struct file_operations fops_zynqmp_pm_dbgfs = {
> > + .owner = THIS_MODULE,
> > + .write = zynqmp_pm_debugfs_api_write,
> > + .read = zynqmp_pm_debugfs_api_version_read,
> > +};
> > +
> > +/**
> > + * zynqmp_pm_api_debugfs_init - Initialize debugfs interface
> > + *
> > + * Return: Returns 0 on success
> > + * Corresponding error code otherwise
> > + */
> > +int zynqmp_pm_api_debugfs_init(void)
> > +{
> > + int err;
> > +
> > + /* Initialize debugfs interface */
> > + zynqmp_pm_debugfs_dir = debugfs_create_dir(DRIVER_NAME, NULL);
> > + if (!zynqmp_pm_debugfs_dir) {
> > + pr_err("debugfs_create_dir failed\n");
> > + return -ENODEV;
> > + }
>
> No, you should NEVER care if a debugfs call returned an error or not, no need to
> check it at all. Your code path should not change based on the return value as
> no code should depened on the functionality of debugfs.
>
> Any error returned by a debugfs call can be passed right back into it with no
> problems, so again, no need to check this.
>
Fixed in v3 patch series. Not saving dentries anymore but added check to show warning message instead of error.
> > +
> > + zynqmp_pm_debugfs_power =
> > + debugfs_create_file("pm", 0220,
> > + zynqmp_pm_debugfs_dir, NULL,
> > + &fops_zynqmp_pm_dbgfs);
> > + if (!zynqmp_pm_debugfs_power) {
> > + pr_err("debugfs_create_file power failed\n");
> > + err = -ENODEV;
> > + goto err_dbgfs;
> > + }
> > +
> > + zynqmp_pm_debugfs_api_version =
> > + debugfs_create_file("api_version", 0444,
> > + zynqmp_pm_debugfs_dir, NULL,
> > + &fops_zynqmp_pm_dbgfs);
> > + if (!zynqmp_pm_debugfs_api_version) {
> > + pr_err("debugfs_create_file api_version failed\n");
> > + err = -ENODEV;
> > + goto err_dbgfs;
> > + }
>
> Why do you save these dentries at all anyway? You never do anything with
> them, just create the files and away you go, no need to worry about anything.
>
> Remember, debugfs was created to be very simple to use, don't make it more
> complex than it has to be please.
>
> thanks,
>
> greg k-h
Fixed in v3 patch series.
Thanks,
Jolly Shah
next prev parent reply other threads:[~2018-01-24 23:33 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-17 20:20 [PATCH v2 0/4] drivers: firmware: xilinx: Add firmware driver support Jolly Shah
[not found] ` <1516220434-22204-1-git-send-email-jollys-gjFFaj9aHVfQT0dZR+AlfA@public.gmane.org>
2018-01-17 20:20 ` [PATCH v2 1/4] dt-bindings: firmware: Add bindings for ZynqMP firmware Jolly Shah
2018-01-17 20:20 ` [PATCH v2 4/4] drivers: firmware: xilinx: Add debugfs interface Jolly Shah
[not found] ` <1516220434-22204-5-git-send-email-jollys-gjFFaj9aHVfQT0dZR+AlfA@public.gmane.org>
2018-01-23 8:41 ` Greg KH
2018-01-24 23:33 ` Jolly Shah [this message]
2018-01-17 20:20 ` [PATCH v2 2/4] drivers: firmware: xilinx: Add ZynqMP firmware driver Jolly Shah
2018-01-23 8:38 ` Greg KH
[not found] ` <20180123083823.GB21463-U8xfFu+wG4EAvxtiuMwx3w@public.gmane.org>
2018-01-24 23:28 ` Jolly Shah
2018-01-17 20:20 ` [PATCH v2 3/4] drivers: firmware: xilinx: Add sysfs interface Jolly Shah
2018-01-23 8:37 ` Greg KH
2018-01-24 23:30 ` Jolly Shah
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