Re: [PATCH 09/14] swim3: clean up request completion paths

Benjamin Herrenschmidt
2009-04-28T06:46:32Z

On Tue, 2009-04-28 at 13:06 +0900, Tejun Heo wrote:
> swim3 curiously tries to update request parameters before calling
> __blk_end_request() when __blk_end_request() will do it anyway, and it
> updates request for partial completion manually instead of using
> blk_update_request(). Also, it does some spurious checks on rq such
> as testing whether rq->sector is negative or current_nr_sectors is
> zero right after fetching.
>
> Drop unnecessary stuff and use standard block layer mechanisms.

That smells like historical stuff from floppy.c :-)

I'll try to dig a mac with a floppy drive to test that.

Cheers,
Ben.

> [ Impact: cleanup ]
>
> Signed-off-by: Tejun Heo <tj@kernel.org>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> ---
> drivers/block/swim3.c | 31 +++++--------------------------
> 1 files changed, 5 insertions(+), 26 deletions(-)
>
> diff --git a/drivers/block/swim3.c b/drivers/block/swim3.c
> index 5904f7b..4248559 100644
> --- a/drivers/block/swim3.c
> +++ b/drivers/block/swim3.c
> @@ -319,14 +319,10 @@ static void start_request(struct floppy_state *fs)
> req->errors, req->current_nr_sectors);
> #endif
>
> - if (req->sector < 0 || req->sector >= fs->total_secs) {
> + if (req->sector >= fs->total_secs) {
> __blk_end_request_cur(req, -EIO);
> continue;
> }
> - if (req->current_nr_sectors == 0) {
> - __blk_end_request_cur(req, 0);
> - continue;
> - }
> if (fs->ejected) {
> __blk_end_request_cur(req, -EIO);
> continue;
> @@ -593,8 +589,6 @@ static void xfer_timeout(unsigned long data)
> struct floppy_state *fs = (struct floppy_state *) data;
> struct swim3 __iomem *sw = fs->swim3;
> struct dbdma_regs __iomem *dr = fs->dma;
> - struct dbdma_cmd *cp = fs->dma_cmd;
> - unsigned long s;
> int n;
>
> fs->timeout_pending = 0;
> @@ -605,14 +599,6 @@ static void xfer_timeout(unsigned long data)
> out_8(&sw->intr_enable, 0);
> out_8(&sw->control_bic, WRITE_SECTORS | DO_ACTION);
> out_8(&sw->select, RELAX);
> - if (rq_data_dir(fd_req) == WRITE)
> - ++cp;
> - if (ld_le16(&cp->xfer_status) != 0)
> - s = fs->scount - ((ld_le16(&cp->res_count) + 511) >> 9);
> - else
> - s = 0;
> - fd_req->sector += s;
> - fd_req->current_nr_sectors -= s;
> printk(KERN_ERR "swim3: timeout %sing sector %ld\n",
> (rq_data_dir(fd_req)==WRITE? "writ": "read"), (long)fd_req->sector);
> __blk_end_request_cur(fd_req, -EIO);
> @@ -719,9 +705,7 @@ static irqreturn_t swim3_interrupt(int irq, void *dev_id)
> if (intr & ERROR_INTR) {
> n = fs->scount - 1 - resid / 512;
> if (n > 0) {
> - fd_req->sector += n;
> - fd_req->current_nr_sectors -= n;
> - fd_req->buffer += n * 512;
> + blk_update_request(fd_req, 0, n << 9);
> fs->req_sector += n;
> }
> if (fs->retries < 5) {
> @@ -745,13 +729,7 @@ static irqreturn_t swim3_interrupt(int irq, void *dev_id)
> start_request(fs);
> break;
> }
> - fd_req->sector += fs->scount;
> - fd_req->current_nr_sectors -= fs->scount;
> - fd_req->buffer += fs->scount * 512;
> - if (fd_req->current_nr_sectors <= 0) {
> - __blk_end_request_cur(fd_req, 0);
> - fs->state = idle;
> - } else {
> + if (__blk_end_request(fd_req, 0, fs->scount << 9)) {
> fs->req_sector += fs->scount;
> if (fs->req_sector > fs->secpertrack) {
> fs->req_sector -= fs->secpertrack;
> @@ -761,7 +739,8 @@ static irqreturn_t swim3_interrupt(int irq, void *dev_id)
> }
> }
> act(fs);
> - }
> + } else
> + fs->state = idle;
> }
> if (fs->state == idle)
> start_request(fs);