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Date: Thu, 12 Mar 2009 00:59:33 -0400
Message-ID: <8bd0f97a0903112159g59c7d414of76e9e4090d8209@mail.gmail.com>
Subject: Re: [PATCH] [net/irda]: new Blackfin on-chip SIR IrDA driver
From: Mike Frysinger <vapier.adi@gmail.com>
To: gyang <graf.yang@analog.com>
Cc: graff yang <graff.yang@gmail.com>, samuel@sortiz.org,
       irda-users@lists.sourceforge.net, linux-kernel@vger.kernel.org,
       cooloney@kernel.org
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On Thu, Mar 12, 2009 at 00:48, gyang wrote:
> On Thu, 2009-03-12 at 00:34 -0400, Mike Frysinger wrote:
>> On Thu, Mar 12, 2009 at 00:30, gyang wrote:
>> > On Thu, 2009-03-12 at 00:23 -0400, Mike Frysinger wrote:
>> >> On Thu, Mar 12, 2009 at 00:17, gyang wrote:
>> >> > On Wed, 2009-03-11 at 06:43 -0400, Mike Frysinger wrote:
>> >> >> On Wed, Mar 11, 2009 at 05:56, graff yang wrote:
>> >> >> > On Wed, Mar 11, 2009 at 3:57 PM, Mike Frysinger wrote:
>> >> >> >> On Wed, Mar 11, 2009 at 03:29,  <graff.yang@gmail.com> wrote:
>> >> >> >>> +static int __devinit bfin_sir_probe(struct platform_device *pdev)
>> >> >> >>> +{
>> >> >> >>> +       struct net_device *dev;
>> >> >> >>> +       struct bfin_sir_self *self;
>> >> >> >>> +       unsigned int baudrate_mask;
>> >> >> >>> +       struct bfin_sir_port *sir_port;
>> >> >> >>> +       int err;
>> >> >> >>> +
>> >> >> >>> +       err = peripheral_request_list(per[pdev->id], DRIVER_NAME);
>> >> >> >>
>> >> >> >> what if pdev->id is set to 12512 ?
>> >> >> >
>> >> >> > The pdev->id is defined in board files, for example, uart0 should be 0.
>> >> >>
>> >> >> so ?  what's to stop the user from setting it to 12415 ?  the driver
>> >> >> must sanity check these things.  you can never assume platform dev
>> >> >> resources always have valid pointers and valid values.
>> >> >
>> >> > How about to limit the pdev->id to be 0,1,2,3 ?
>> >> > I can extend the per to be
>> >> > static const unsigned short per[][4] = {
>> >> >        {P_UART0_RX, P_UART0_TX, 0, 0},
>> >> >        {P_UART1_RX, P_UART1_TX, 0, 1},
>> >> >        {P_UART2_RX, P_UART2_TX, 0, 2},
>> >> >        {P_UART3_RX, P_UART3_TX, 0, 3},
>> >> > };
>> >> >
>> >> > then check (pdev->id >= 0 && pdev->id < ARRAY_SIZE(per) &&
>> >> > per[pdev->id][3] == pdev->id)
>> >>
>> >> the last check is redundant.  the first two should be added.
>> >
>> > I'm afraid of some cases such as uart0 uses id 1, will cause driver not
>> > work, and not any warning message.
>>
>> then the call to peripheral request would fail as expected
>
> For example, user want to enable irda on uart2 for bf548, he use id 0
> for uart2. In these case, peripheral request may not fail, but driver
> not work.

the id is wrong then.  if they want uart2, then they should use id 2.
-mike
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