Re: [PATCH 2/2] mtd: msm_nand: Add initial msm nand driver support.

[Murali Nalajala <mnalajal@codeaurora.org>]

On 4/15/2011 3:21 PM, Artem Bityutskiy wrote:
> On Tue, 2011-03-01 at 06:17 +0530, Murali Nalajala wrote:
>> +#define pr_fmt(fmt) "%s:" fmt, __func__
>> +
>> +#include<linux/kernel.h>
>> +#include<linux/mtd/mtd.h>
>> +#include<linux/mtd/nand.h>
>> +#include<linux/mtd/partitions.h>
>> +#include<linux/platform_device.h>
>> +#include<linux/sched.h>
>> +#include<linux/slab.h>
>> +#include<linux/dma-mapping.h>
>> +#include<asm/mach/flash.h>
>> +#include<mach/dma.h>
>> +
>> +#include "msm_nand.h"
>> +
>> +unsigned long msm_nand_phys;
>
> No global variables like this please. Here is how you use them:
>
> +extern unsigned long msm_nand_phys;

extern declaration in the 'C' file causing warning. We are in plan to 
upload the OneNAND changes soon which makes use of the same .h file.

> +#define MSM_NAND_REG(off) (msm_nand_phys + (off))
> +
> +#define MSM_NAND_FLASH_CMD            MSM_NAND_REG(0x0000)
> +#define MSM_NAND_ADDR0                MSM_NAND_REG(0x0004)
>
> Could you please make the macros to take the "struct msm_nand_chip
> *chip" argument instead, and store the pase address there. Do not hide
> the fact that those macros are actually functions, not constant - this
> is error prone.
>
> Besides, I'm do not know your HW, but if you have several controllers
> with various base addresses - your driver won't work.

you are correct, we have multiple controllers, which breaks this logic 
in future.

>
>> +	pr_info("Save cfg0 = %x cfg1 = %x\n", chip->cfg0, chip->cfg1);
>> +	pr_info("cfg0: cw/page=%d ud_sz=%d ecc_sz=%d spare_sz=%d "
>> +		"num_addr_cycles=%d\n", (chip->cfg0>>  6)&  7,
>> +		(chip->cfg0>>  9)&  0x3ff, (chip->cfg0>>  19)&  15,
>> +		(chip->cfg0>>  23)&  15, (chip->cfg0>>  27)&  7);
>
> Please, revise all your pr_info() calls and turn most of them into
> dev_dbg() or pr_debug. Your driver should be completely silent by
> default, except of error messages and some information messages when it
> is initialized.
>
>
I will revise all the pr_info calls and change the inappropriate calls 
to pr_debug.

Thanks,
Murali N

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