Changeset c657bd7 in mainline

Timestamp:

2017-11-20T10:06:59Z (6 years ago)

Author:

Jiri Svoboda <jiri@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

19ea61d

Parents:

5d50c419

git-author:

Jiri Svoboda <jiri@…> (2017-11-19 22:05:26)

git-committer:

Jiri Svoboda <jiri@…> (2017-11-20 10:06:59)

Message:

Less is sometimes more. Need chardev_read to be able to return less bytes than requested if less is available. Otherwise cannot read variable-sized packets except yte-by-byte.

Location:

uspace

Files:

• drv/char/i8042/buffer.h (modified) (2 diffs)
• drv/char/i8042/i8042.c (modified) (1 diff)
• drv/char/pl050/pl050.c (modified) (2 diffs)
• drv/hid/ps2mouse/ps2mouse.c (modified) (5 diffs)
• drv/hid/xtkbd/xtkbd.c (modified) (1 diff)
• lib/c/generic/io/chardev.c (modified) (3 diffs)

uspace/drv/char/i8042/buffer.h

@@ -113 +113 @@
  *
  * @param buffer Cyclic buffer to read from.
+ * @param rb Place to store byte read
+ * @param wait @c True to wait until byte is available
  *
- * @return Byte read.
+ * @return EOK on success, EAGAIN if @c wait is false and no data is available
  *
  */
-static inline uint8_t buffer_read(buffer_t *buffer)
+static inline int buffer_read(buffer_t *buffer, uint8_t *rb, bool wait)
 {
         fibril_mutex_lock(&buffer->guard);
         
         /* Buffer is empty. */
-        while (buffer->write_head == buffer->read_head)
+        while (wait && buffer->write_head == buffer->read_head)
                 fibril_condvar_wait(&buffer->change, &buffer->guard);
+        
+        if (buffer->write_head == buffer->read_head) {
+                fibril_mutex_unlock(&buffer->guard);
+                return EAGAIN;
+        }
         
         /* Next position. */
@@ -144 +151 @@
         
         fibril_mutex_unlock(&buffer->guard);
-        return data;
+        *rb = data;
+        return EOK;
 }
 

uspace/drv/char/i8042/i8042.c

@@ -374 +374 @@
         i8042_t *i8042 = port->ctl;
         uint8_t *destp = (uint8_t *)dest;
+        int rc;
+        size_t i;
         
         buffer_t *buffer = (port == i8042->aux) ?
             &i8042->aux_buffer : &i8042->kbd_buffer;
         
-        for (size_t i = 0; i < size; ++i)
-                *destp++ = buffer_read(buffer);
-        
-        return size;
+        for (i = 0; i < size; ++i) {
+                rc = buffer_read(buffer, destp, i == 0);
+                if (rc != EOK)
+                        break;
+                ++destp;
+        }
+        
+        return i;
 }
 

uspace/drv/char/pl050/pl050.c

@@ -246 +246 @@
         left = size;
         while (left > 0) {
-                while (pl050->buf_rp == pl050->buf_wp)
+                while (left == size && pl050->buf_rp == pl050->buf_wp)
                         fibril_condvar_wait(&pl050->buf_cv, &pl050->buf_lock);
+                if (pl050->buf_rp == pl050->buf_wp)
+                        break;
                 *bp++ = pl050->buffer[pl050->buf_rp];
                 --left;
@@ -255 +257 @@
         fibril_mutex_unlock(&pl050->buf_lock);
 
-        return size;
+        return size - left;
 }
 

uspace/drv/hid/ps2mouse/ps2mouse.c

@@ -212 +212 @@
 }
 
+/** Read fixed-size mouse packet.
+ *
+ * Continue reading until entire packet is received.
+ *
+ * @param mouse Mouse device
+ * @param pbuf Buffer for storing packet
+ * @param psize Packet size
+ *
+ * @return EOK on success or non-zero error code
+ */
+static int ps2_mouse_read_packet(ps2_mouse_t *mouse, void *pbuf, size_t psize)
+{
+        int rc;
+        size_t pos;
+        size_t nread;
+
+        pos = 0;
+        while (pos < psize) {
+                rc = chardev_read(mouse->chardev, pbuf + pos, psize - pos,
+                    &nread);
+                if (rc != EOK) {
+                        ddf_msg(LVL_WARN, "Error reading packet.");
+                        return rc;
+                }
+
+                pos += nread;
+        }
+
+        return EOK;
+}
+
 /** Get data and parse ps2 protocol packets.
  * @param arg Pointer to ps2_mouse_t structure.
@@ -219 +250 @@
 {
         ps2_mouse_t *mouse = (ps2_mouse_t *) arg;
-        size_t nread;
         int rc;
 
@@ -225 +255 @@
         while (1) {
                 uint8_t packet[PS2_BUFSIZE] = {};
-                rc = chardev_read(mouse->chardev, packet, PS2_BUFSIZE, &nread);
-                if (rc != EOK || nread != PS2_BUFSIZE) {
-                        ddf_msg(LVL_WARN, "Incorrect packet size: %zd.", nread);
+                rc = ps2_mouse_read_packet(mouse, packet, PS2_BUFSIZE);
+                if (rc != EOK)
                         continue;
-                }
 
                 ddf_msg(LVL_DEBUG2, "Got packet: %hhx:%hhx:%hhx.",
@@ -274 +302 @@
 {
         ps2_mouse_t *mouse = (ps2_mouse_t *) arg;
-        size_t nread;
         int rc;
 
@@ -280 +307 @@
         while (1) {
                 uint8_t packet[INTELLIMOUSE_BUFSIZE] = {};
-                rc = chardev_read(mouse->chardev, packet, INTELLIMOUSE_BUFSIZE,
-                    &nread);
-                if (rc != EOK || nread != INTELLIMOUSE_BUFSIZE) {
-                        ddf_msg(LVL_WARN, "Incorrect packet size: %zd.", nread);
+                rc = ps2_mouse_read_packet(mouse, packet, INTELLIMOUSE_BUFSIZE);
+                if (rc != EOK)
                         continue;
-                }
+
                 ddf_msg(LVL_DEBUG2, "Got packet: %hhx:%hhx:%hhx:%hhx.",
                     packet[0], packet[1], packet[2], packet[3]);

uspace/drv/hid/xtkbd/xtkbd.c

@@ -353 +353 @@
                 
                 size_t nwr;
-                int rc = chardev_write(kbd->chardev, cmds, sizeof(cmds), &nwr);
-                if (nwr != sizeof(cmds))
-                        rc = EIO;
-
+                int rc = chardev_write(kbd->chardev, &cmds[0], 1, &nwr);
+                if (rc != EOK) {
+                        async_answer_0(icallid, rc);
+                        break;
+                }
+
+                rc = chardev_write(kbd->chardev, &cmds[1], 1, &nwr);
                 async_answer_0(icallid, rc);
                 break;

uspace/lib/c/generic/io/chardev.c

@@ -77 +77 @@
 }
 
-int chardev_read(chardev_t *chardev, void *data, size_t size, size_t *nread)
+/** Read from character device.
+ *
+ * Read as much data as is available from character device up to @a size
+ * bytes into @a buf. On success EOK is returned and at least one byte
+ * is read (if no byte is available the function blocks). The number
+ * of bytes read is stored in @a *nread.
+ *
+ * On error a non-zero error code is returned and @a *nread is filled with
+ * the number of bytes that were successfully transferred.
+ *
+ * @param chardev Character device
+ * @param buf Destination buffer
+ * @param size Maximum number of bytes to read
+ * @param nread Place to store actual number of bytes read
+ *
+ * @return EOK on success or non-zero error code
+ */
+int chardev_read(chardev_t *chardev, void *buf, size_t size, size_t *nread)
 {
         if (size > 4 * sizeof(sysarg_t))
@@ -88 +105 @@
         async_exchange_end(exch);
         if (ret > 0 && (size_t)ret <= size)
-                memcpy(data, message, size);
+                memcpy(buf, message, size);
 
         if (ret < 0) {
@@ -99 +116 @@
 }
 
+/** Write to character device.
+ *
+ * Write @a size bytes from @a data to character device. On success EOK
+ * is returned, all bytes were written and @a *nwritten is set to @a size.
+ *
+ * On error a non-zero error code is returned and @a *nwritten is filled with
+ * the number of bytes that were successfully transferred.
+ *
+ * @param chardev Character device
+ * @param buf Destination buffer
+ * @param size Maximum number of bytes to read
+ * @param nwritten Place to store actual number of bytes written
+ *
+ * @return EOK on success or non-zero error code
+ */
 int chardev_write(chardev_t *chardev, const void *data, size_t size,
     size_t *nwritten)