Re: [PATCH v2 00/19] mtd: rawnand: cafe: Convert to exec_op() (and more)

[Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>]

On Thu, 7 May 2020 15:47:08 +0200
Lubomir Rintel <lkundrak@xxxxx> wrote:

> On Wed, May 06, 2020 at 11:35:52PM +0200, Boris Brezillon wrote:
> > On Wed, 6 May 2020 22:36:35 +0200
> > Lubomir Rintel <lkundrak@xxxxx> wrote:
> >   
> > > > We really should mask IRQs (AKA disable IRQs in my naming convention
> > > > :-)) here, unless we want to switch to interrupt-based waits (which
> > > > would be a good thing when we have DMA or WAIT_RDY involved). Having an
> > > > interrupt handler in the current implementation doesn't make any sense
> > > > (that's assuming the IRQ_STATUS bits are updated even if the interrupts
> > > > are disabled, which am not sure is a valid assumption in this case).    
> > > 
> > > I have no idea why the interrupt handler is there. Perhaps some
> > > interrupts can't be masked and need an ack or something.  
> > 
> > Can you try to set NAND_IRQ_MASK to 0x0 and see if that still works.
> > Can you also check the number of NAND interrupts when set to 0x0? It's
> > hard to tell exactly what caused the interrupt handler to be called
> > since this is a shared interrupt.  
> 
> When it's set to 0, I get an interrupt with CAFE_NAND_IRQ=0x40000000
> (CAFE_NAND_IRQ_FLASH_RDY) right off the bat. That doesn't happen with
> a mask of 0xffffffff.
> 
> When changing the handler to always ack CAFE_NAND_IRQ_FLASH_RDY I've
> also seen CAFE_NAND_IRQ=0x80000000 (CAFE_NAND_IRQ_CMD_DONE) suggesting
> that other interrupts aren't masked either.
> 
> It seems to be that ones indeed mask interrupts but just can't be
> masked (CAFE_NAND_IRQ_CMD_DONE or CAFE_NAND_IRQ_DMA_DONE), perhaps
> due to hardware bugs.
> 

I pushed a new version with some interrupt-related changes [1].

[1]https://github.com/bbrezillon/linux/commits/nand/cafe-nand-exec-op-debug


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