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    SubjectRe: [PATCH 1/2 v2] Driver for Freescale 8610 and 5121 DIU
    On Fri, 21 Mar 2008 11:12:30 -0500 Timur Tabi <timur@freescale.com> wrote:

    > Andrew Morton wrote:
    >
    > >> +static struct diu_hw dr = {
    > >> + .mode = MFB_MODE1,
    > >> + .reg_lock = __SPIN_LOCK_UNLOCKED(old_style_spin_init),
    > >> +};
    > >
    > > I'm not clear on what's supposed to happen with __SPIN_LOCK_UNLOCKED(). I
    > > do know that its documentation is crap.
    >
    > Yes, "__SPIN_LOCK_UNLOCKED(old_style_spin_init)" is wrong. We'll fix it.
    >
    > > static struct diu_hw dr = {
    > > .mode = MFB_MODE1,
    > > - .reg_lock = __SPIN_LOCK_UNLOCKED(old_style_spin_init),
    > > + .reg_lock = __SPIN_LOCK_UNLOCKED(diu_hw.reg_lock),
    > > };
    >
    > Yes, this is better. Did you already make this change when you applied it to
    > your -mm repo?

    I did:

    --- a/drivers/video/fsl-diu-fb.c~fbdev-driver-for-freescale-8610-and-5121-diu-fix
    +++ a/drivers/video/fsl-diu-fb.c
    @@ -274,7 +274,7 @@ static struct mfb_info mfb_template[] =

    static struct diu_hw dr = {
    .mode = MFB_MODE1,
    - .reg_lock = __SPIN_LOCK_UNLOCKED(old_style_spin_init),
    + .reg_lock = __SPIN_LOCK_UNLOCKED(dr.reg_lock),
    };

    static struct diu_pool pool;
    > > GFP_DMA implies GFP_ATOMIC, but it's appropriate for documentation purposes.
    >
    > So does that mean that "GFP_DMA | GFP_KERNEL" is always wrong?

    No, that's OK too. It's just that GFP_DMA|GFP_ATOMIC is a bit redundant
    and misleading. GFP_DMA is already atomic; the only effect of adding
    GFP_ATOMIC to GFP_DMA is to add __GFP_HIGH.
    Don't wory about it ;)

    > If so, this
    > combination is used a lot in the kernel today.
    >
    > >> + if (virt) {
    > >> + *phys = virt_to_phys(virt);
    > >> + pr_debug("virt %p, phys=%llx\n", virt, (uint64_t) *phys);
    > >> + memset(virt, 0, size);
    > >
    > > Could have used __GFP_ZERO, I guess.
    >
    > I had completely forgotten about __GFP_ZERO. Thanks.
    >
    > >> + virt = (void *) rh_alloc(&diu_ops.diu_rh_info, size, "DIU");
    > >
    > > hm, I'd have expected checkpatch to whine about the space after the cast
    > > there. Whatever.
    >
    > I thought a space after a cast is the right thing to do?

    Last time I grepped, no-space is a lot more common.

    > > please take a look, and please use checkpatch on all future patches.
    >
    > Sorry, we forgot to run it again after our second version of the patch.
    >
    > >> +static void free_irq_local(int irq)
    > >> +{
    > >> + struct diu *hw = dr.diu_reg;
    > >> +
    > >> + /* Disable all LCDC interrupt */
    > >> + out_be32(&(hw->int_mask), 0x1f);
    > >> +
    > >> + free_irq(irq, 0);
    > >> +}
    > >
    > > and the free_irq() will go splat?
    >
    > Sorry, but I don't understand what's wrong with this code.

    You snipped a bit. Earlier, request_irq() failures were ignored. So I
    think there's a code path where free_irq_local() can free an IRQ which this
    driver never owned.

    > We'll make the other changes you've suggested and repost.



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