Re: [PATCH 1/2] amiga floppy: Stop sharing request queue across multiple gendisks

[Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>]

On Thu, Sep 23, 2010 at 21:54, Vivek Goyal <vgoyal@xxxxxxxxxx> wrote:
> o Use one request queue per gendisk instead of sharing request queue
>
> o Don't have hardware. No compile testing or run time testing done. Completely
> Âuntested.
>
> Signed-off-by: Vivek Goyal <vgoyal@xxxxxxxxxx>
> ---
> Âdrivers/block/amiflop.c | Â 59 ++++++++++++++++++++++++++++++++++++++--------
> Â1 files changed, 48 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/block/amiflop.c b/drivers/block/amiflop.c
> index 76f114f..ead8b77 100644
> --- a/drivers/block/amiflop.c
> +++ b/drivers/block/amiflop.c
> @@ -114,8 +114,6 @@ static unsigned long int fd_def_df0 = FD_DD_3; Â Â /* default for df0 if it does
> Âmodule_param(fd_def_df0, ulong, 0);
> ÂMODULE_LICENSE("GPL");
>
> -static struct request_queue *floppy_queue;
> -
> Â/*
> Â* ÂMacros
> Â*/
> @@ -164,6 +162,7 @@ static volatile int selected = -1; Â/* currently selected drive */
> Âstatic int writepending;
> Âstatic int writefromint;
> Âstatic char *raw_buf;
> +static int fdc_queue;
>
> Âstatic DEFINE_SPINLOCK(amiflop_lock);
>
> @@ -1334,6 +1333,42 @@ static int get_track(int drive, int track)
> Â Â Â Âreturn -1;
> Â}
>
> +/*
> + * Round-robin between our available drives, doing one request from each
> + */
> +static struct request *set_next_request(void)
> +{
> + Â Â Â struct request_queue *q;
> + Â Â Â int cnt = FD_MAX_UNITS;
> + Â Â Â struct request *rq;
> +
> + Â Â Â /* Find next queue we can dispatch from */
> + Â Â Â fdc_queue = fdc_queue + 1;
> + Â Â Â if (fdc_queue == FD_MAX_UNITS)
> + Â Â Â Â Â Â Â fdc_queue = 0;
> +
> + Â Â Â for(cnt = FD_MAX_UNITS; cnt > 0, cnt--) {
> +
> + Â Â Â Â Â Â Â if (unit[fdc_queue].type->code == FD_NODRIVE) {
> + Â Â Â Â Â Â Â Â Â Â Â if (++fdc_queue == FD_MAX_UNITS)
> + Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â fdc_queue = 0;
> + Â Â Â Â Â Â Â Â Â Â Â cotinue;
> + Â Â Â Â Â Â Â }
> +
> + Â Â Â Â Â Â Â q = unit[fdc_queue].gendisk->queue;
> + Â Â Â Â Â Â Â if (q) {
> + Â Â Â Â Â Â Â Â Â Â Â rq = blk_fetch_request(q);
> + Â Â Â Â Â Â Â Â Â Â Â if (rq)
> + Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â break;
> + Â Â Â Â Â Â Â }
> +
> + Â Â Â Â Â Â Â if (++fdc_queue == FD_MAX_UNITS)
> + Â Â Â Â Â Â Â Â Â Â Â fdc_queue = 0;
> + Â Â Â }
> +
> + Â Â Â return rq;
> +}

drivers/block/amiflop.c:1344: warning: ârqâ may be used uninitialized
in this function
drivers/block/ataflop.c:1402: warning: ârqâ may be used uninitialized
in this function

Should `rq' just be initialized to NULL? I looked at
floppy.c:set_next_request(), but it's
completely different.

Gr{oetje,eeting}s,

            Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
             Â Â -- Linus Torvalds
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