From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1.linux-foundation.org (smtp1.linux-foundation.org [140.211.169.13]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "smtp.linux-foundation.org", Issuer "CA Cert Signing Authority" (verified OK)) by ozlabs.org (Postfix) with ESMTPS id 1E8E3DDE06 for ; Sat, 22 Mar 2008 05:13:26 +1100 (EST) Date: Fri, 21 Mar 2008 11:12:28 -0700 From: Andrew Morton To: Timur Tabi Subject: Re: [PATCH 1/2 v2] Driver for Freescale 8610 and 5121 DIU Message-Id: <20080321111228.95a7d9ab.akpm@linux-foundation.org> In-Reply-To: <47E3DE6E.2050801@freescale.com> References: <12059526271941-git-send-email-yorksun@freescale.com> <12059526274026-git-send-email-yorksun@freescale.com> <20080320152708.23c6c734.akpm@linux-foundation.org> <47E3DE6E.2050801@freescale.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Cc: linux-fbdev-devel@lists.sourceforge.net, Peter Zijlstra , linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org, York Sun List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, 21 Mar 2008 11:12:30 -0500 Timur Tabi 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.