Messages in this thread | | | Date | Tue, 17 May 2011 11:24:17 +0530 | From | viresh kumar <> | Subject | Re: [PATCH] dw_dmac: Replace subsys_init() with arch_initcall() |
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On 05/17/2011 09:13 AM, Koul, Vinod wrote: > On Tue, 2011-05-17 at 09:36 +0530, viresh kumar wrote: >> On 05/16/2011 09:36 PM, Koul, Vinod wrote: >>> On Mon, 2011-05-16 at 10:20 +0530, Viresh Kumar wrote: >>>> In some cases users of dw_dmac, amba-pl022, are initialized before dw_dmac, and >>>> if they try to use dw_dmac, they simply fail. So its better we register init() >>>> routine of driver using arch_initcall() instead of subsys_init(), so that dma >>>> driver is available at the earliest possible. >>>> >>>> Signed-off-by: Viresh Kumar <viresh.kumar@st.com> >>>> --- >>>> drivers/dma/dw_dmac.c | 2 +- >>>> 1 files changed, 1 insertions(+), 1 deletions(-) >>>> >>>> diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c >>>> index 54d72a8..4b580e7 100644 >>>> --- a/drivers/dma/dw_dmac.c >>>> +++ b/drivers/dma/dw_dmac.c >>>> @@ -1566,7 +1566,7 @@ static int __init dw_init(void) >>>> { >>>> return platform_driver_probe(&dw_driver, dw_probe); >>>> } >>>> -subsys_initcall(dw_init); >>>> +arch_initcall(dw_init); >>> arch_init is usually kept for subystem initialization. >>> Why cant you move the amba-pl022 init to module_init, that should take >>> care of this. >>> >> >> Actually, amba-pl022 init was moved to subsys_initcall earlier with >> following patch: >> >> And so i moved dma's init to arch_initcall. Also the similar approach is >> taken by drivers/dma/ste_dma40.c >> >> Also, maybe it makes more sense for dma to be up at the earliest. >> Isn't it? > > As I said before arch init is supposed to used for initialization of the > subsystems not for a driver init. > You need to ensure that with given init levels and makefile order your > dependencies are properly resolved, rather than this approach. > > Like move whatever dependent on amba to late_init and amba to module > init, that would be advisable approach rather than above. >
As i said earlier, with following patch from Linus:
commit 25c8e03bdb769dfe2381f8b7942f05b0eb4bdf31 Author: Linus Walleij <linus.walleij@stericsson.com> Date: Mon Sep 6 11:02:12 2010 +0200
spi/pl022: move probe call to subsys_initcall()
The PL022 SPI bus is sometimes used for early stuff like regulators that need to be present at module_init() time, so we move this to a subsys_initcall().
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca> --- drivers/spi/amba-pl022.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)
SPI bus is required for regulators and so probably he can't have module_init() for amba-pl022. And so, DMA has nothing more than arch_initcall().
@Linus: What do you say? Can we get back to module_init() for amba-pl022? And subsys_initcall() for DMA.
-- viresh
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