linux-kernel - Re: [PATCH V5 05/12] mailbox: Add NVIDIA Tegra XUSB mailbox driver

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAJe_ZhdTvZZqERttAM_o6U6MZCOjk=oXpWFPf8W=DdW1j=Nx=g@mail.gmail.com>
Date:	Mon, 24 Nov 2014 14:04:49 +0530
From:	Jassi Brar <jaswinder.singh@...aro.org>
To:	Andrew Bresticker <abrestic@...omium.org>
Cc:	Stephen Warren <swarren@...dotorg.org>,
	Thierry Reding <thierry.reding@...il.com>,
	Alexandre Courbot <gnurou@...il.com>,
	"linux-tegra@...r.kernel.org" <linux-tegra@...r.kernel.org>,
	Mark Rutland <mark.rutland@....com>,
	Devicetree List <devicetree@...r.kernel.org>,
	Linux USB list <linux-usb@...r.kernel.org>,
	Russell King <linux@....linux.org.uk>,
	Mathias Nyman <mathias.nyman@...el.com>,
	Pawel Moll <pawel.moll@....com>,
	Ian Campbell <ijc+devicetree@...lion.org.uk>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Linus Walleij <linus.walleij@...aro.org>,
	Jassi Brar <jassisinghbrar@...il.com>,
	lkml <linux-kernel@...r.kernel.org>,
	Kishon Vijay Abraham I <kishon@...com>,
	Olof Johansson <olof@...om.net>,
	Rob Herring <robh+dt@...nel.org>,
	Alan Stern <stern@...land.harvard.edu>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	Kumar Gala <galak@...eaurora.org>,
	Grant Likely <grant.likely@...aro.org>,
	Arnd Bergmann <arnd@...db.de>
Subject: Re: [PATCH V5 05/12] mailbox: Add NVIDIA Tegra XUSB mailbox driver

On 18 November 2014 at 04:11, Andrew Bresticker <abrestic@...omium.org> wrote:

> +
> +static int tegra_xusb_mbox_send_data(struct mbox_chan *chan, void *data)
> +{
> +       struct tegra_xusb_mbox *mbox = to_tegra_mbox(chan->mbox);
> +       struct tegra_xusb_mbox_msg *msg = data;
> +       unsigned long flags;
> +       u32 reg, owner;
> +
> +       dev_dbg(mbox->mbox.dev, "TX message %#x:%#x\n", msg->cmd, msg->data);
> +
> +       /* ACK/NAK must be sent with the controller as the mailbox owner */
> +       if (msg->cmd == MBOX_CMD_ACK || msg->cmd == MBOX_CMD_NAK)
> +               owner = MBOX_OWNER_FW;
> +       else
> +               owner = MBOX_OWNER_SW;
> +
> +       spin_lock_irqsave(&mbox->lock, flags);
> +
> +       /* Acquire mailbox */
> +       if (mbox_readl(mbox, XUSB_CFG_ARU_MBOX_OWNER) != MBOX_OWNER_NONE) {
> +               dev_err(mbox->mbox.dev, "Mailbox not idle\n");
> +               goto busy;
> +       }
> +       mbox_writel(mbox, owner, XUSB_CFG_ARU_MBOX_OWNER);
> +       if (mbox_readl(mbox, XUSB_CFG_ARU_MBOX_OWNER) != owner) {
> +               dev_err(mbox->mbox.dev, "Failed to acquire mailbox");
> +               goto busy;
> +       }
> +
> +       mbox_writel(mbox, mbox_pack_msg(msg), XUSB_CFG_ARU_MBOX_DATA_IN);
> +       reg = mbox_readl(mbox, XUSB_CFG_ARU_MBOX_CMD);
> +       reg |= MBOX_INT_EN | MBOX_DEST_FALC;
> +       mbox_writel(mbox, reg, XUSB_CFG_ARU_MBOX_CMD);
> +
> +       spin_unlock_irqrestore(&mbox->lock, flags);
> +
> +       return 0;
> +busy:
> +       spin_unlock_irqrestore(&mbox->lock, flags);
> +       return -EBUSY;
> +}
> +
> +static int tegra_xusb_mbox_startup(struct mbox_chan *chan)
> +{
> +       return 0;
> +}
> +
> +static void tegra_xusb_mbox_shutdown(struct mbox_chan *chan)
> +{
> +}
> +
> +static bool tegra_xusb_mbox_last_tx_done(struct mbox_chan *chan)
> +{
> +       /*
> +        * Transmissions are assumed to be completed as soon as they are
> +        * written to the mailbox.
> +        */
> +       return true;
>
In .send_data() you you mark the channel busy by setting the
XUSB_CFG_ARU_MBOX_OWNER to !MBOX_OWNER_NONE, which remains so until
you get an IRQ. So maybe you should check for the OWNER_NONE flag in
.last_tx_done()?

-Jassi
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/