Re: [PATCH resend] ide/libata: fix ata_id_is_cfa() (take 4)

[Jeff Garzik <jgarzik@pobox.com>]

Sergei Shtylyov wrote:
> When checking for the CFA feature set support, ata_id_is_cfa() tests bit 2 in
> word 82 of the identify data instead the word 83;  it also checks the ATA/PI
> version support in the word 80 (which the CompactFlash specifications have as
> reserved), this having no slightest chance to work on the modern CF cards that
> don't have 0x848A in the word 0...
> 
> Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
> 
> ---
> Oops, caught the comment typos, resending... :-/
> So, here's the fourth version of this simplistic patch in which I had to drop
> the paranoid ATA version check since apparently not all cards follow the CF
> specs in this respect and it seems wrong to blacklist a card that does report
> CFA feature set support...
> 
>  include/linux/ata.h |   15 ++++++++++-----
>  1 files changed, 10 insertions(+), 5 deletions(-)
> 
> Index: linux-2.6/include/linux/ata.h
> ===================================================================
> --- linux-2.6.orig/include/linux/ata.h
> +++ linux-2.6/include/linux/ata.h
> @@ -731,12 +731,17 @@ static inline int ata_id_current_chs_val
>  
>  static inline int ata_id_is_cfa(const u16 *id)
>  {
> -	if (id[ATA_ID_CONFIG] == 0x848A)	/* Standard CF */
> +	if (id[ATA_ID_CONFIG] == 0x848A)	/* Traditional CF */
>  		return 1;
> -	/* Could be CF hiding as standard ATA */
> -	if (ata_id_major_version(id) >= 3 &&
> -	    id[ATA_ID_COMMAND_SET_1] != 0xFFFF &&
> -	   (id[ATA_ID_COMMAND_SET_1] & (1 << 2)))
> +	/*
> +	 * CF specs don't require specific value in the word 0 anymore and yet
> +	 * they forbid to report the ATA version in the word 80 and require the
> +	 * CFA feature set support to be indicated in the word 83 in this case.
> +	 * Unfortunately, some cards only follow either of this requirements,
> +	 * and while those that don't indicate CFA feature support need some
> +	 * sort of quirk list, it seems impractical for the ones that do...
> +	 */
> +	if ((id[ATA_ID_COMMAND_SET_2] & 0xC004) == 0x4004)
>  		return 1;
>  	return 0;
>  }

applied to libata tree...