From 5b21f9dddd0817b761f1407f1950bee4f257411a Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Tue, 17 Jul 2007 04:05:17 -0700 Subject: [PATCH] Char: isicom, cleanup locking Don't spin processor when not needed (use sleep instead of delay). Don't release the lock when needed in next iteration -- this actually fixes a bug -- missing braces Signed-off-by: Jiri Slaby Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/char/isicom.c | 65 ++++++++++++++++++------------------------- 1 file changed, 27 insertions(+), 38 deletions(-) diff --git a/drivers/char/isicom.c b/drivers/char/isicom.c index 761f77740d67..b133b92a0ad5 100644 --- a/drivers/char/isicom.c +++ b/drivers/char/isicom.c @@ -243,17 +243,18 @@ static inline int WaitTillCardIsFree(u16 base) static int lock_card(struct isi_board *card) { - char retries; unsigned long base = card->base; + unsigned int retries, a; - for (retries = 0; retries < 100; retries++) { + for (retries = 0; retries < 10; retries++) { spin_lock_irqsave(&card->card_lock, card->flags); - if (inw(base + 0xe) & 0x1) { - return 1; - } else { - spin_unlock_irqrestore(&card->card_lock, card->flags); - udelay(1000); /* 1ms */ + for (a = 0; a < 10; a++) { + if (inw(base + 0xe) & 0x1) + return 1; + udelay(10); } + spin_unlock_irqrestore(&card->card_lock, card->flags); + msleep(10); } printk(KERN_WARNING "ISICOM: Failed to lock Card (0x%lx)\n", card->base); @@ -261,23 +262,6 @@ static int lock_card(struct isi_board *card) return 0; /* Failed to acquire the card! */ } -static int lock_card_at_interrupt(struct isi_board *card) -{ - unsigned char retries; - unsigned long base = card->base; - - for (retries = 0; retries < 200; retries++) { - spin_lock_irqsave(&card->card_lock, card->flags); - - if (inw(base + 0xe) & 0x1) - return 1; - else - spin_unlock_irqrestore(&card->card_lock, card->flags); - } - /* Failing in interrupt is an acceptable event */ - return 0; /* Failed to acquire the card! */ -} - static void unlock_card(struct isi_board *card) { spin_unlock_irqrestore(&card->card_lock, card->flags); @@ -415,6 +399,8 @@ static inline int __isicom_paranoia_check(struct isi_port const *port, static void isicom_tx(unsigned long _data) { + unsigned long flags; + unsigned int retries; short count = (BOARD_COUNT-1), card, base; short txcount, wrd, residue, word_count, cnt; struct isi_port *port; @@ -435,32 +421,34 @@ static void isicom_tx(unsigned long _data) count = isi_card[card].port_count; port = isi_card[card].ports; base = isi_card[card].base; + + spin_lock_irqsave(&isi_card[card].card_lock, flags); + for (retries = 0; retries < 100; retries++) { + if (inw(base + 0xe) & 0x1) + break; + udelay(2); + } + if (retries >= 100) + goto unlock; + for (;count > 0;count--, port++) { - if (!lock_card_at_interrupt(&isi_card[card])) - continue; /* port not active or tx disabled to force flow control */ if (!(port->flags & ASYNC_INITIALIZED) || !(port->status & ISI_TXOK)) - unlock_card(&isi_card[card]); continue; tty = port->tty; - - if (tty == NULL) { - unlock_card(&isi_card[card]); + if (tty == NULL) continue; - } txcount = min_t(short, TX_SIZE, port->xmit_cnt); - if (txcount <= 0 || tty->stopped || tty->hw_stopped) { - unlock_card(&isi_card[card]); + if (txcount <= 0 || tty->stopped || tty->hw_stopped) continue; - } - if (!(inw(base + 0x02) & (1 << port->channel))) { - unlock_card(&isi_card[card]); + + if (!(inw(base + 0x02) & (1 << port->channel))) continue; - } + pr_dbg("txing %d bytes, port%d.\n", txcount, port->channel + 1); outw((port->channel << isi_card[card].shift_count) | txcount, @@ -508,9 +496,10 @@ static void isicom_tx(unsigned long _data) port->status &= ~ISI_TXOK; if (port->xmit_cnt <= WAKEUP_CHARS) tty_wakeup(tty); - unlock_card(&isi_card[card]); } +unlock: + spin_unlock_irqrestore(&isi_card[card].card_lock, flags); /* schedule another tx for hopefully in about 10ms */ sched_again: if (!re_schedule) { -- 2.34.1