[U-Boot] [PATCH v2] ppc/85xx: PIO Support for FSL eSDHC Controller Driver

[Dudhat Dipen-B09055]

Hi Wolfgang,

There are some IP specific requirements to get the transaction complete
in PIO mode.

Thanks
Dipen


-----Original Message-----
From: Wolfgang Denk [mailto:wd at denx.de] 
Sent: Wednesday, September 23, 2009 12:12 AM
To: Dudhat Dipen-B09055
Cc: u-boot at lists.denx.de
Subject: Re: [U-Boot] [PATCH v2] ppc/85xx: PIO Support for FSL eSDHC
Controller Driver

Dear Dipen Dudhat,

In message <1252589856-4970-1-git-send-email-dipen.dudhat at freescale.com>
you wrote:
> On some Freescale SoC Internal DMA of eSDHC controller has bug.
> 
> So PIO Mode has introduced to do data transfer using CPU.
> In PIO mode data transfer performance will be degraded by a large
extent.
> 
> Note: 
> In PIO mode multiple block read/write requires delay to complete the
transfer.

Does that mean you just delay, i. e. you do not check for some ready
state?


...
> --- a/include/fsl_esdhc.h
> +++ b/include/fsl_esdhc.h
> @@ -86,6 +86,7 @@
>  #define PRSSTAT_CDPL		(0x00040000)
>  #define PRSSTAT_CINS		(0x00010000)
>  #define PRSSTAT_BREN		(0x00000800)
> +#define PRSSTAT_BWEN		(0x00000400)
>  #define PRSSTAT_DLA		(0x00000004)
>  #define PRSSTAT_CICHB		(0x00000002)
>  #define PRSSTAT_CIDHB		(0x00000001)
> @@ -117,6 +118,7 @@
>  #define XFERTYP_DMAEN		0x00000001
>  
>  #define CINS_TIMEOUT		1000
> +#define MAX_TIMEOUT		100000

MAX_TIMEOUT is a very generic name, please chose a more specific one so
interactions with other code are prevented. (Also, TIMEOUT itself
already means a maximum time, so MAX_TIMEOUT is a tautology.)

Dipen,    
Will update that.



Best regards,

Wolfgang Denk

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