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| author | Ondrej Zary <linux@rainbow-software.org> | 2007-11-14 16:59:24 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-11-14 18:45:39 -0800 |
| commit | e62aa046e1748b8ea0354951685478030392cf56 (patch) | |
| tree | 075f0698a025da5518d70ad90336d42aa09ffb52 /drivers/block | |
| parent | ba0a7f39ce8cd54a1b2f3adb03509ff251a91bde (diff) | |
| download | linux-stable-e62aa046e1748b8ea0354951685478030392cf56.tar.gz linux-stable-e62aa046e1748b8ea0354951685478030392cf56.tar.bz2 linux-stable-e62aa046e1748b8ea0354951685478030392cf56.zip | |
paride: pf driver fixes
The pf driver for parallel port floppy drives seems to be broken. At least
with Imation SuperDisk with EPAT chip, the driver calls pi_connect() and
pi_disconnect after each transferred sector. At least with EPAT, this
operation is very expensive - causes drive recalibration. Thus, transferring
even a single byte (dd if=/dev/pf0 of=/dev/null bs=1 count=1) takes 20
seconds, making the driver useless.
The pf_next_buf() function seems to be broken as it returns 1 always (except
when pf_run is non-zero), causing the loop in do_pf_read_drq (and
do_pf_write_drq) to be executed only once.
The following patch fixes this problem. It also fixes swapped descriptions in
pf_lock() function and removes DBMSG macro, which seems useless.
Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/block')
| -rw-r--r-- | drivers/block/paride/pf.c | 25 |
1 files changed, 14 insertions, 11 deletions
diff --git a/drivers/block/paride/pf.c b/drivers/block/paride/pf.c index ceffa6034e20..e7fe6ca97dd8 100644 --- a/drivers/block/paride/pf.c +++ b/drivers/block/paride/pf.c @@ -488,13 +488,11 @@ static int pf_atapi(struct pf_unit *pf, char *cmd, int dlen, char *buf, char *fu return r; } -#define DBMSG(msg) ((verbose>1)?(msg):NULL) - static void pf_lock(struct pf_unit *pf, int func) { char lo_cmd[12] = { ATAPI_LOCK, pf->lun << 5, 0, 0, func, 0, 0, 0, 0, 0, 0, 0 }; - pf_atapi(pf, lo_cmd, 0, pf_scratch, func ? "unlock" : "lock"); + pf_atapi(pf, lo_cmd, 0, pf_scratch, func ? "lock" : "unlock"); } static void pf_eject(struct pf_unit *pf) @@ -555,7 +553,7 @@ static void pf_mode_sense(struct pf_unit *pf) { ATAPI_MODE_SENSE, pf->lun << 5, 0, 0, 0, 0, 0, 0, 8, 0, 0, 0 }; char buf[8]; - pf_atapi(pf, ms_cmd, 8, buf, DBMSG("mode sense")); + pf_atapi(pf, ms_cmd, 8, buf, "mode sense"); pf->media_status = PF_RW; if (buf[3] & 0x80) pf->media_status = PF_RO; @@ -591,7 +589,7 @@ static void pf_get_capacity(struct pf_unit *pf) char buf[8]; int bs; - if (pf_atapi(pf, rc_cmd, 8, buf, DBMSG("get capacity"))) { + if (pf_atapi(pf, rc_cmd, 8, buf, "get capacity")) { pf->media_status = PF_NM; return; } @@ -804,13 +802,18 @@ static int pf_next_buf(void) pf_buf += 512; pf_block++; if (!pf_run) - return 0; - if (!pf_count) return 1; - spin_lock_irqsave(&pf_spin_lock, saved_flags); - pf_end_request(1); - spin_unlock_irqrestore(&pf_spin_lock, saved_flags); - return 1; + if (!pf_count) { + spin_lock_irqsave(&pf_spin_lock, saved_flags); + pf_end_request(1); + pf_req = elv_next_request(pf_queue); + spin_unlock_irqrestore(&pf_spin_lock, saved_flags); + if (!pf_req) + return 1; + pf_count = pf_req->current_nr_sectors; + pf_buf = pf_req->buffer; + } + return 0; } static inline void next_request(int success) |