re: block: Add driver for Micron RealSSD pcie flash cards

re: block: Add driver for Micron RealSSD pcie flash cards

[Dan Carpenter]

Hello Sam Bradshaw,

The patch 88523a61558a: "block: Add driver for Micron RealSSD pcie 
flash cards" from Aug 30, 2011, creates an endian bug:
drivers/block/mtip32xx/mtip32xx.c:2468 mtip_hw_submit_io()

drivers/block/mtip32xx/mtip32xx.c
  2465          fis->opts        = 1 << 7;
  2466          fis->command     =
  2467                  (dir == READ ? ATA_CMD_FPDMA_READ : ATA_CMD_FPDMA_WRITE);
  2468          *((unsigned int *) &fis->lba_low) = (start & 0xFFFFFF);
                                    ^^^^^^^^^^^^
  2469          *((unsigned int *) &fis->lba_low_ex) = ((start >> 24) & 0xFFFFFF);
                                    ^^^^^^^^^^^^^^^

These addresses point to a series of four unions inside the
host_to_dev_fis struct.  The unions will be set to different values
depending on if the CPU is big or little endian.

If you knew which endianness this works on, then you could probably add
a cpu_to_be32() or cpu_to_le32().

  2470          fis->device      = 1 << 6;
  2471          fis->features    = nsect & 0xFF;

regards,
dan carpenter

RE: block: Add driver for Micron RealSSD pcie flash cards

[Sam Bradshaw (sbradshaw)]

> -----Original Message-----
> From: Dan Carpenter [mailto:dan.carpenter@oracle.com]
> Sent: Monday, October 08, 2012 12:13 AM
> To: Sam Bradshaw (sbradshaw)
> Cc: Jens Axboe; linux-kernel@vger.kernel.org
> Subject: re: block: Add driver for Micron RealSSD pcie flash cards
> 
> Hello Sam Bradshaw,
> 
> The patch 88523a61558a: "block: Add driver for Micron RealSSD pcie
> flash cards" from Aug 30, 2011, creates an endian bug:
> drivers/block/mtip32xx/mtip32xx.c:2468 mtip_hw_submit_io()
> 
> drivers/block/mtip32xx/mtip32xx.c
>   2465          fis->opts        = 1 << 7;
>   2466          fis->command     =
>   2467                  (dir == READ ? ATA_CMD_FPDMA_READ : ATA_CMD_FPDMA_WRITE);
>   2468          *((unsigned int *) &fis->lba_low) = (start & 0xFFFFFF);
>                                     ^^^^^^^^^^^^
>   2469          *((unsigned int *) &fis->lba_low_ex) = ((start >> 24) & 0xFFFFFF);
>                                     ^^^^^^^^^^^^^^^
> 
> These addresses point to a series of four unions inside the
> host_to_dev_fis struct.  The unions will be set to different values
> depending on if the CPU is big or little endian.
> 
> If you knew which endianness this works on, then you could probably add
> a cpu_to_be32() or cpu_to_le32().

Thanks for the notification; we'll get a patch out asap.

-Sam