From: notaz Date: Thu, 2 Oct 2014 23:33:13 +0000 (+0300) Subject: teensy3lib: do level masking instead of disable X-Git-Url: https://notaz.gp2x.de/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1ad7d1ddee4bb654f8b8a8420516fcc39fc0f68d;p=megadrive.git teensy3lib: do level masking instead of disable we need to avoid higher priority irq latency --- diff --git a/teensy3/kinetis.h b/teensy3/kinetis.h index fe6a938..c2af4fa 100644 --- a/teensy3/kinetis.h +++ b/teensy3/kinetis.h @@ -2551,6 +2551,17 @@ typedef struct __attribute__((packed)) { #define __disable_irq() __asm__ volatile("CPSID i"); #define __enable_irq() __asm__ volatile("CPSIE i"); +/* only mask default irqs, see NVIC_SET_PRIORITY users + * note: usb code uses 112 priority */ +#define __mask_irq() do { \ + int basepri_ = 128 - 16; \ + __asm__ volatile("msr BASEPRI, %0" :: "r"(basepri_)); \ +} while (0) +#define __unmask_irq() do { \ + int basepri_ = 0; \ + __asm__ volatile("msr BASEPRI, %0" :: "r"(basepri_)); \ +} while (0) + // System Control Space (SCS), ARMv7 ref manual, B3.2, page 708 #define SCB_CPUID (*(const uint32_t *)0xE000ED00) // CPUID Base Register #define SCB_ICSR (*(volatile uint32_t *)0xE000ED04) // Interrupt Control and State diff --git a/teensy3/usb_dev.c b/teensy3/usb_dev.c index e87f158..5ff8726 100644 --- a/teensy3/usb_dev.c +++ b/teensy3/usb_dev.c @@ -531,13 +531,13 @@ usb_packet_t *usb_rx(uint32_t endpoint) usb_packet_t *ret; endpoint--; if (endpoint >= NUM_ENDPOINTS) return NULL; - __disable_irq(); + __mask_irq(); ret = rx_first[endpoint]; if (ret) { rx_first[endpoint] = ret->next; usb_rx_byte_count_data[endpoint] -= ret->len; } - __enable_irq(); + __unmask_irq(); //serial_print("rx, epidx="); //serial_phex(endpoint); //serial_print(", packet="); @@ -550,11 +550,11 @@ static uint32_t usb_queue_byte_count(const usb_packet_t *p) { uint32_t count=0; - __disable_irq(); + __mask_irq(); for ( ; p; p = p->next) { count += p->len; } - __enable_irq(); + __unmask_irq(); return count; } @@ -583,9 +583,9 @@ uint32_t usb_tx_packet_count(uint32_t endpoint) endpoint--; if (endpoint >= NUM_ENDPOINTS) return 0; - __disable_irq(); + __mask_irq(); for (p = tx_first[endpoint]; p; p = p->next) count++; - __enable_irq(); + __unmask_irq(); return count; } @@ -605,14 +605,14 @@ void usb_rx_memory(usb_packet_t *packet) cfg = usb_endpoint_config_table; //serial_print("rx_mem:"); - __disable_irq(); + __mask_irq(); for (i=1; i <= NUM_ENDPOINTS; i++) { if (*cfg++ & USB_ENDPT_EPRXEN) { if (table[index(i, RX, EVEN)].desc == 0) { table[index(i, RX, EVEN)].addr = packet->buf; table[index(i, RX, EVEN)].desc = BDT_DESC(64, 0); usb_rx_memory_needed--; - __enable_irq(); + __unmask_irq(); //serial_phex(i); //serial_print(",even\n"); return; @@ -621,14 +621,14 @@ void usb_rx_memory(usb_packet_t *packet) table[index(i, RX, ODD)].addr = packet->buf; table[index(i, RX, ODD)].desc = BDT_DESC(64, 1); usb_rx_memory_needed--; - __enable_irq(); + __unmask_irq(); //serial_phex(i); //serial_print(",odd\n"); return; } } } - __enable_irq(); + __unmask_irq(); // we should never reach this point. If we get here, it means // usb_rx_memory_needed was set greater than zero, but no memory // was actually needed. @@ -647,7 +647,7 @@ void usb_tx(uint32_t endpoint, usb_packet_t *packet) endpoint--; if (endpoint >= NUM_ENDPOINTS) return; - __disable_irq(); + __mask_irq(); //serial_print("txstate="); //serial_phex(tx_state[endpoint]); //serial_print("\n"); @@ -673,13 +673,13 @@ void usb_tx(uint32_t endpoint, usb_packet_t *packet) tx_last[endpoint]->next = packet; } tx_last[endpoint] = packet; - __enable_irq(); + __unmask_irq(); return; } tx_state[endpoint] = next; b->addr = packet->buf; b->desc = BDT_DESC(packet->len, ((uint32_t)b & 8) ? DATA1 : DATA0); - __enable_irq(); + __unmask_irq(); }