Re: [PATCH] mmc: sdhci-msm: Make tuning block table endian agnostic

[Jaehoon Chung <jh80.chung@samsung.com>]

Hi, Stephen.

On 09/03/2014 10:57 PM, Stephen Boyd wrote:
> If we're tuning on a big-endian CPU we'll never determine we properly
> tuned the device because we compare the data we received from the
> controller with a table that assumes the CPU is little-endian.
> Change the table to be an array of bytes instead of 32-bit words
> so we can use memcmp() without needing to byte-swap every word
> depending on the endianess of the CPU.
> 
> Cc: Asutosh Das <asutoshd@codeaurora.org>
> Cc: Venkat Gopalakrishnan <venkatg@codeaurora.org>
> Reviewed-by: Georgi Djakov <gdjakov@mm-sol.com>
> Fixes: 415b5a75da43 "mmc: sdhci-msm: Add platform_execute_tuning implementation"
> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
> ---
>  drivers/mmc/host/sdhci-msm.c | 42 +++++++++++++++++++++++++++---------------
>  1 file changed, 27 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
> index 40573a58486a..5aabffc15ae8 100644
> --- a/drivers/mmc/host/sdhci-msm.c
> +++ b/drivers/mmc/host/sdhci-msm.c
> @@ -47,22 +47,34 @@
>  #define CMUX_SHIFT_PHASE_SHIFT	24
>  #define CMUX_SHIFT_PHASE_MASK	(7 << CMUX_SHIFT_PHASE_SHIFT)
>  
> -static const u32 tuning_block_64[] = {
> -	0x00ff0fff, 0xccc3ccff, 0xffcc3cc3, 0xeffefffe,
> -	0xddffdfff, 0xfbfffbff, 0xff7fffbf, 0xefbdf777,
> -	0xf0fff0ff, 0x3cccfc0f, 0xcfcc33cc, 0xeeffefff,
> -	0xfdfffdff, 0xffbfffdf, 0xfff7ffbb, 0xde7b7ff7
> +static const u8 tuning_block_64[] = {
> +	0xff, 0x0f, 0xff, 0x00, 0xff, 0xcc, 0xc3, 0xcc,
> +	0xc3, 0x3c, 0xcc, 0xff, 0xfe, 0xff, 0xfe, 0xef,
> +	0xff, 0xdf, 0xff, 0xdd, 0xff, 0xfb, 0xff, 0xfb,
> +	0xbf, 0xff, 0x7f, 0xff, 0x77, 0xf7, 0xbd, 0xef,
> +	0xff, 0xf0, 0xff, 0xf0, 0x0f, 0xfc, 0xcc, 0x3c,
> +	0xcc, 0x33, 0xcc, 0xcf, 0xff, 0xef, 0xff, 0xee,
> +	0xff, 0xfd, 0xff, 0xfd, 0xdf, 0xff, 0xbf, 0xff,
> +	0xbb, 0xff, 0xf7, 0xff, 0xf7, 0x7f, 0x7b, 0xde,
>  };
>  
> -static const u32 tuning_block_128[] = {
> -	0xff00ffff, 0x0000ffff, 0xccccffff, 0xcccc33cc,
> -	0xcc3333cc, 0xffffcccc, 0xffffeeff, 0xffeeeeff,
> -	0xffddffff, 0xddddffff, 0xbbffffff, 0xbbffffff,
> -	0xffffffbb, 0xffffff77, 0x77ff7777, 0xffeeddbb,
> -	0x00ffffff, 0x00ffffff, 0xccffff00, 0xcc33cccc,
> -	0x3333cccc, 0xffcccccc, 0xffeeffff, 0xeeeeffff,
> -	0xddffffff, 0xddffffff, 0xffffffdd, 0xffffffbb,
> -	0xffffbbbb, 0xffff77ff, 0xff7777ff, 0xeeddbb77
> +static const u8 tuning_block_128[] = {
> +	0xff, 0xff, 0x00, 0xff, 0xff, 0xff, 0x00, 0x00,
> +	0xff, 0xff, 0xcc, 0xcc, 0xcc, 0x33, 0xcc, 0xcc,
> +	0xcc, 0x33, 0x33, 0xcc, 0xcc, 0xcc, 0xff, 0xff,
> +	0xff, 0xee, 0xff, 0xff, 0xff, 0xee, 0xee, 0xff,
> +	0xff, 0xff, 0xdd, 0xff, 0xff, 0xff, 0xdd, 0xdd,
> +	0xff, 0xff, 0xff, 0xbb, 0xff, 0xff, 0xff, 0xbb,
> +	0xbb, 0xff, 0xff, 0xff, 0x77, 0xff, 0xff, 0xff,
> +	0x77, 0x77, 0xff, 0x77, 0xbb, 0xdd, 0xee, 0xff,
> +	0xff, 0xff, 0xff, 0x00, 0xff, 0xff, 0xff, 0x00,
> +	0x00, 0xff, 0xff, 0xcc, 0xcc, 0xcc, 0x33, 0xcc,
> +	0xcc, 0xcc, 0x33, 0x33, 0xcc, 0xcc, 0xcc, 0xff,
> +	0xff, 0xff, 0xee, 0xff, 0xff, 0xff, 0xee, 0xee,
> +	0xff, 0xff, 0xff, 0xdd, 0xff, 0xff, 0xff, 0xdd,
> +	0xdd, 0xff, 0xff, 0xff, 0xbb, 0xff, 0xff, 0xff,
> +	0xbb, 0xbb, 0xff, 0xff, 0xff, 0x77, 0xff, 0xff,
> +	0xff, 0x77, 0x77, 0xff, 0x77, 0xbb, 0xdd, 0xee,
>  };
In dw-mmc.c, tuning_block values are same.
So I think we can move these value into generic header. how about?

Best Regards,
Jaehoon Chung

>  
>  struct sdhci_msm_host {
> @@ -359,7 +371,7 @@ static int sdhci_msm_execute_tuning(struct sdhci_host *host, u32 opcode)
>  {
>  	int tuning_seq_cnt = 3;
>  	u8 phase, *data_buf, tuned_phases[16], tuned_phase_cnt = 0;
> -	const u32 *tuning_block_pattern = tuning_block_64;
> +	const u8 *tuning_block_pattern = tuning_block_64;
>  	int size = sizeof(tuning_block_64);	/* Pattern size in bytes */
>  	int rc;
>  	struct mmc_host *mmc = host->mmc;
>