From: Pavan Holla <pholla@chromium.org>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>,
Benson Leung <bleung@chromium.org>,
Tzung-Bi Shih <tzungbi@kernel.org>,
Guenter Roeck <groeck@chromium.org>,
linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org,
Abhishek Pandit-Subedi <abhishekpandit@chromium.org>,
chrome-platform@lists.linux.dev
Subject: Re: [PATCH v4 2/2] usb: typec: ucsi: Implement ChromeOS UCSI driver
Date: Wed, 10 Apr 2024 15:27:43 -0700 [thread overview]
Message-ID: <CAB2FV=6We88NrvN8NZYt8NkMFH9N_ZBGyUWVUpGwPdja2X_+NA@mail.gmail.com> (raw)
In-Reply-To: <2024040916-kleenex-machinist-4858@gregkh>
I plan to upload the next version after related EC changes land on
ChromeOS. That might take a few weeks.
On Tue, Apr 9, 2024 at 8:16 AM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> On Tue, Apr 09, 2024 at 02:27:37AM +0000, Pavan Holla wrote:
> > +#define DRV_NAME "cros-ec-ucsi"
>
> KBUILD_MODNAME?
Will replace DRV_NAME with KBUILD_MODNAME.
> > +
> > +#define MAX_EC_DATA_SIZE 256
> > +#define WRITE_TMO_MS 500
>
> What are these and why these values? And tabs perhaps?
MAX_EC_DATA_SIZE is the number of bytes that can be read or written to in the
UCSI data structure using a single host command to the EC.
WRITE_TMO_MS is the time within which a cmd complete or ack notification must
arrive after a command is sent to the PPM.
Will add comments and tabs.
> > + uint8_t ec_buffer[MAX_EC_DATA_SIZE + sizeof(struct ec_params_ucsi_ppm_set)];
>
> That's a lot of data on the stack, are you sure you want to do that?
>
> And are you sure you are allowed to have this data on the stack? It
> never ends up being sent using DMA?
I confirmed that this data isn't DMA'ed. However, I don't mind putting
it on the heap, and will do so in the next version.
> And please, don't use non-kernel types like "uint8_t", use "u8" like
> intended. This isn't userspace (yes, I know a lot of kernel code uses
> these, but as you are going to change this, might as well change that
> too.)
Ack.
Thanks,
Pavan
prev parent reply other threads:[~2024-04-10 22:28 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-09 2:27 [PATCH v4 0/2] usb: typec: Implement UCSI driver for ChromeOS Pavan Holla
2024-04-09 2:27 ` [PATCH v4 1/2] platform/chrome: Update ChromeOS EC header for UCSI Pavan Holla
2024-04-09 2:27 ` [PATCH v4 2/2] usb: typec: ucsi: Implement ChromeOS UCSI driver Pavan Holla
2024-04-09 10:47 ` Tzung-Bi Shih
2024-04-10 22:14 ` Pavan Holla
2024-04-09 15:16 ` Greg Kroah-Hartman
2024-04-10 22:27 ` Pavan Holla [this message]
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