From: arighi <arighi@38d2e660-2303-0410-9eaa-f027e97ec537>
Date: Fri, 18 Feb 2011 23:55:18 +0000 (+0000)
Subject: STM32: USB: correctly detect when read/write must be called without blocking
X-Git-Tag: 2.7.0~249
X-Git-Url: https://codewiz.org/gitweb?a=commitdiff_plain;h=80ac3ae104b48f42eb8911de0879a477cf812a4c;p=bertos.git

STM32: USB: correctly detect when read/write must be called without blocking

Read or write operations with the EP0 may happen within the USB
interrupt.

Make the driver able to understand when the usb_endpointRead() or
usb_endpointWrite() is called from the interrupt context or not.

Basically, only the even callbacks concerning the EP0 should be called
in a interrupt context. For all the other cases the user must take care
of using usb_endpointRead() and usb_endointWrite() from a non-atomic
(sleepable) context.

git-svn-id: https://src.develer.com/svnoss/bertos/trunk@4717 38d2e660-2303-0410-9eaa-f027e97ec537
---

diff --git a/bertos/cpu/cortex-m3/drv/usb_stm32.c b/bertos/cpu/cortex-m3/drv/usb_stm32.c
index 794aa891..ac3f55fa 100644
--- a/bertos/cpu/cortex-m3/drv/usb_stm32.c
+++ b/bertos/cpu/cortex-m3/drv/usb_stm32.c
@@ -160,6 +160,9 @@ static uint8_t ep_buffer[EP_MAX_NUM][EP_BUFFER_SIZE] ALIGNED(4);
 
 static Event usb_event_done[EP_MAX_SLOTS];
 
+/* Check if we're running in atomic (non-sleepable) context or not */
+static volatile bool in_atomic = false;
+
 /* Allocate a free block of the packet memory */
 static stm32_UsbMemSlot *usb_malloc(void)
 {
@@ -1129,7 +1132,7 @@ ssize_t usb_endpointRead(int ep, void *buffer, ssize_t size)
 	ssize_t max_size = sizeof(ep_buffer[ep_num]);
 
 	/* Non-blocking read for EP0 */
-	if (ep_num == CTRL_ENP_OUT)
+	if (in_atomic && (ep_num == CTRL_ENP_OUT))
 	{
 		size = usb_size(size, usb_le16_to_cpu(setup_packet.wLength));
 		if (UNLIKELY(size > max_size))
@@ -1183,7 +1186,7 @@ ssize_t usb_endpointWrite(int ep, const void *buffer, ssize_t size)
 	ssize_t max_size = sizeof(ep_buffer[ep_num]);
 
 	/* Non-blocking write for EP0 */
-	if (ep_num == CTRL_ENP_IN)
+	if (in_atomic && (ep_num == CTRL_ENP_IN))
 	{
 		size = usb_size(size, usb_le16_to_cpu(setup_packet.wLength));
 		if (UNLIKELY(size > max_size))
@@ -1806,6 +1809,9 @@ static void usb_isr(void)
 	interrupt.status = usb->ISTR;
 	interrupt.status &= usb->CNTR | 0x1f;
 
+	/* Set the context as atomic */
+	in_atomic = true;
+
 	if (interrupt.PMAOVR)
 	{
 		LOG_WARN("%s: DMA overrun / underrun\n", __func__);
@@ -1855,6 +1861,7 @@ static void usb_isr(void)
 	{
 		usb_isr_correct_transfer(interrupt);
 	}
+	in_atomic = false;
 }
 
 /* USB: hardware initialization */