From: Jiri Slaby Date: Mon, 5 Mar 2012 13:52:17 +0000 (+0100) Subject: TTY: simserial, remove support of shared interrupts X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=964105b501071e8a0e9feb1d0e4b3e46508bc38e;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git TTY: simserial, remove support of shared interrupts It never worked there. The ISR was never written for that kind of stuff. So remove all that crap with a hash of linked lists and pass the pointer directly to the ISR. BTW this answers the question there: * I don't know exactly why they don't use the dev_id opaque data * pointer instead of this extra lookup table -> Because they thought they will support more devices bound to a single interrupt w/o IRQF_SHARED. They would need exactly the hash there. What I don't understand is rebinding of the interrupt in the shutdown path. They perhaps meant to do just synchronize_irq? In any case, this is all gone and free_irq there properly. By removing the hash we save some bits (exactly NR_IRQS * 8 bytes of .bss and over a kilo of .text): before: text data bss dec hex filename 19600 320 8227 28147 6df3 ../a/ia64/arch/ia64/hp/sim/simserial.o after: text data bss dec hex filename 18568 320 28 18916 49e4 ../a/ia64/arch/ia64/hp/sim/simserial.o Note that a shared interrupt could not work too. request_irq requires data parameter to be non-NULL. So the whole IRQ_T exercise was pointless. Finally, this helps us remove another two members of async_struct :). Signed-off-by: Jiri Slaby Cc: Tony Luck Cc: Fenghua Yu Signed-off-by: Greg Kroah-Hartman --- diff --git a/arch/ia64/hp/sim/simserial.c b/arch/ia64/hp/sim/simserial.c index d32b759b23f1..c35552df035e 100644 --- a/arch/ia64/hp/sim/simserial.c +++ b/arch/ia64/hp/sim/simserial.c @@ -92,8 +92,6 @@ static struct serial_uart_config uart_config[] = { struct tty_driver *hp_simserial_driver; -static struct async_struct *IRQ_ports[NR_IRQS]; - static struct console *console; static unsigned char *tmp_buf; @@ -167,14 +165,9 @@ static void receive_chars(struct tty_struct *tty) */ static irqreturn_t rs_interrupt_single(int irq, void *dev_id) { - struct async_struct * info; + struct async_struct *info = dev_id; - /* - * I don't know exactly why they don't use the dev_id opaque data - * pointer instead of this extra lookup table - */ - info = IRQ_ports[irq]; - if (!info || !info->tty) { + if (!info->tty) { printk(KERN_INFO "simrs_interrupt_single: info|tty=0 info=%p problem\n", info); return IRQ_NONE; } @@ -456,7 +449,6 @@ static void shutdown(struct async_struct * info) { unsigned long flags; struct serial_state *state = info->state; - int retval; if (!(state->flags & ASYNC_INITIALIZED)) return; @@ -468,33 +460,8 @@ static void shutdown(struct async_struct * info) local_irq_save(flags); { - /* - * First unlink the serial port from the IRQ chain... - */ - if (info->next_port) - info->next_port->prev_port = info->prev_port; - if (info->prev_port) - info->prev_port->next_port = info->next_port; - else - IRQ_ports[state->irq] = info->next_port; - - /* - * Free the IRQ, if necessary - */ - if (state->irq && (!IRQ_ports[state->irq] || - !IRQ_ports[state->irq]->next_port)) { - if (IRQ_ports[state->irq]) { - free_irq(state->irq, NULL); - retval = request_irq(state->irq, rs_interrupt_single, - IRQ_T(state), "serial", - NULL); - - if (retval) - printk(KERN_ERR "serial shutdown: request_irq: error %d" - " Couldn't reacquire IRQ.\n", retval); - } else - free_irq(state->irq, NULL); - } + if (state->irq) + free_irq(state->irq, info); if (info->xmit.buf) { free_page((unsigned long) info->xmit.buf); @@ -645,7 +612,6 @@ startup(struct async_struct *info) { unsigned long flags; int retval=0; - irq_handler_t handler; struct serial_state *state= info->state; unsigned long page; @@ -677,29 +643,13 @@ startup(struct async_struct *info) /* * Allocate the IRQ if necessary */ - if (state->irq && (!IRQ_ports[state->irq] || - !IRQ_ports[state->irq]->next_port)) { - if (IRQ_ports[state->irq]) { - retval = -EBUSY; - goto errout; - } else - handler = rs_interrupt_single; - - retval = request_irq(state->irq, handler, IRQ_T(state), - "simserial", NULL); + if (state->irq) { + retval = request_irq(state->irq, rs_interrupt_single, + IRQ_T(state), "simserial", info); if (retval) goto errout; } - /* - * Insert serial port into IRQ chain. - */ - info->prev_port = NULL; - info->next_port = IRQ_ports[state->irq]; - if (info->next_port) - info->next_port->prev_port = info; - IRQ_ports[state->irq] = info; - if (info->tty) clear_bit(TTY_IO_ERROR, &info->tty->flags); info->xmit.head = info->xmit.tail = 0; diff --git a/include/linux/serialP.h b/include/linux/serialP.h index 6ce488c46589..b8543f902453 100644 --- a/include/linux/serialP.h +++ b/include/linux/serialP.h @@ -56,8 +56,6 @@ struct async_struct { wait_queue_head_t open_wait; wait_queue_head_t close_wait; wait_queue_head_t delta_msr_wait; - struct async_struct *next_port; /* For the linked list */ - struct async_struct *prev_port; }; #endif /* _LINUX_SERIAL_H */