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Reply-To: vadivel.muruganx.ramuthevar@linux.intel.com
Subject: Re: [PATCH v4 2/2] mtd: rawnand: Add NAND controller support on Intel
 LGM SoC
To:     Boris Brezillon <boris.brezillon@collabora.com>
Cc:     linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org,
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References: <20200429104205.18780-1-vadivel.muruganx.ramuthevar@linux.intel.com>
 <20200429104205.18780-3-vadivel.muruganx.ramuthevar@linux.intel.com>
 <20200429162249.55d38ee8@collabora.com>
From:   "Ramuthevar, Vadivel MuruganX" 
        <vadivel.muruganx.ramuthevar@linux.intel.com>
Message-ID: <9d77c64c-d0f9-7a13-3391-d05bf458bdb1@linux.intel.com>
Date:   Wed, 29 Apr 2020 22:33:37 +0800
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Hi Boris,

On 29/4/2020 10:22 pm, Boris Brezillon wrote:
> On Wed, 29 Apr 2020 18:42:05 +0800
> "Ramuthevar, Vadivel MuruganX"
> <vadivel.muruganx.ramuthevar@linux.intel.com> wrote:
> 
>> +
>> +#define EBU_ADDR_SEL(n)		(0x20 + (n) * 4)
>> +#define EBU_ADDR_MASK		(5 << 4)
> 
> It's still unclear what ADDR_MASK is for. Can you add a comment
> explaining what it does?

Thank you Boris, keep review and giving inputs, will update.
> 
>> +#define EBU_ADDR_SEL_REGEN	0x1
> 
> 
>> +
>> +	writel(lower_32_bits(ebu_host->cs[ebu_host->cs_num].nand_pa) |
>> +	       EBU_ADDR_SEL_REGEN | EBU_ADDR_MASK,
>> +	       ebu_host->ebu + EBU_ADDR_SEL(reg));
>> +
>> +	writel(EBU_MEM_BASE_CS_0 | EBU_ADDR_MASK | EBU_ADDR_SEL_REGEN,
>> +	       ebu_host->ebu + EBU_ADDR_SEL(0));
>> +	writel(EBU_MEM_BASE_CS_1 | EBU_ADDR_MASK | EBU_ADDR_SEL_REGEN,
>> +	       ebu_host->ebu + EBU_ADDR_SEL(reg));
> 
> That's super weird. You seem to set EBU_ADDR_SEL(reg) twice. Are you
> sure that's needed, and are we setting EBU_ADDR_SEL(0) here?

You are right, its weird only, but we need it, since different chip 
select has different memory region access address.

Yes , we are setting both CS0 and CS1 memory access region, if you have 
any concern to optimize, please suggest me, Thanks!

Regards
Vadivel
>