On Wed, 6 Jun 2012, Namjae Jeon wrote:
> Add support write cache quirk on usb hdd. scsi driver will be set to wce by detecting write cache quirk in quirk list when plugging usb hdd.
>
> Signed-off-by: Namjae Jeon <namjae.jeon@xxxxxxxxxxx>
> Signed-off-by: Pankaj Kumar <pankaj.km@xxxxxxxxxxx>
> Signed-off-by: Amit Sahrawat <a.sahrawat@xxxxxxxxxxx>
> ---
> drivers/usb/storage/scsiglue.c | 6 ++++++
> drivers/usb/storage/usb.c | 5 ++++-
> include/linux/usb/quirks.h | 3 +++
> include/linux/usb_usual.h | 4 +++-
> 4 files changed, 16 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/usb/storage/scsiglue.c b/drivers/usb/storage/scsiglue.c
> index a324a5d..f7d0ea5 100644
> --- a/drivers/usb/storage/scsiglue.c
> +++ b/drivers/usb/storage/scsiglue.c
> @@ -51,6 +51,7 @@
> #include <scsi/scsi_devinfo.h>
> #include <scsi/scsi_device.h>
> #include <scsi/scsi_eh.h>
> +#include <linux/usb/quirks.h>
>
> #include "usb.h"
> #include "scsiglue.h"
> @@ -230,6 +231,11 @@ static int slave_configure(struct scsi_device *sdev)
> US_FL_SCM_MULT_TARG)) &&
> us->protocol == USB_PR_BULK)
> us->use_last_sector_hacks = 1;
> +
> + /* Check for the cache quirk present or not */
> + if (us->pusb_dev->quirks & USB_QUIRK_WRITE_CACHE ||
> + us->fflags & US_FL_WRITE_CACHE)
> + sdev->wce_quirk = 1;
This is very wrong. Your new quirk should be added only to us->fflags,
not to us->pusb_dev->quirks.
> --- a/drivers/usb/storage/usb.c
> +++ b/drivers/usb/storage/usb.c
> @@ -473,7 +473,7 @@ static void adjust_quirks(struct us_data *us)
> US_FL_CAPACITY_OK | US_FL_IGNORE_RESIDUE |
> US_FL_SINGLE_LUN | US_FL_NO_WP_DETECT |
> US_FL_NO_READ_DISC_INFO | US_FL_NO_READ_CAPACITY_16 |
> - US_FL_INITIAL_READ10);
> + US_FL_INITIAL_READ10 | US_FL_WRITE_CACHE);
>
> p = quirks;
> while (*p) {
> @@ -538,6 +538,9 @@ static void adjust_quirks(struct us_data *us)
> case 'w':
> f |= US_FL_NO_WP_DETECT;
> break;
> + case 'p':
> + f |= US_FL_WRITE_CACHE;
> + break;
These cases are in alphabetical order. Please keep them that way.
Also, if you're going to change a module parameter like this then you
_must_ update the description in Documentation/kernel-parameters.txt.
> --- a/include/linux/usb/quirks.h
> +++ b/include/linux/usb/quirks.h
> @@ -30,4 +30,7 @@
> descriptor */
> #define USB_QUIRK_DELAY_INIT 0x00000040
>
> +/* Device can't handle cache status request */
> +#define USB_QUIRK_WRITE_CACHE 0x00000080
As mentioned above, this is wrong.
> --- a/include/linux/usb_usual.h
> +++ b/include/linux/usb_usual.h
> @@ -64,7 +64,9 @@
> US_FLAG(NO_READ_CAPACITY_16, 0x00080000) \
> /* cannot handle READ_CAPACITY_16 */ \
> US_FLAG(INITIAL_READ10, 0x00100000) \
> - /* Initial READ(10) (and others) must be retried */
> + /* Initial READ(10) (and others) must be retried */ \
> + US_FLAG(WRITE_CACHE, 0x00200000) \
And this is right. But please try to make your '\' characters line up
with the existing ones.
> + /* Cache read status is not correct */
This comment, however is wrong. The flag applies when the cache status
is not _available_ rather than when it is not _correct_.
Alan Stern
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