debugging exif, added packed attribute to structures

src/drivers/elphel/exif393.c

@@ -501,7 +501,7 @@ loff_t exif_lseek  (struct file * file, loff_t offset, int orig) {
 	int p=(int)file->private_data;
 	int thissize=minor_file_size(p);
 	int maxsize=minor_max_size(p);
-//    int fp;
+    int fp;
     dev_dbg(g_devfp_ptr,"exif_lseek, minor=%d, offset = 0x%llx, orig=%d\n",p,offset,orig);
 	//   int sensor_port;
 	switch (orig) {
@@ -548,10 +548,12 @@ loff_t exif_lseek  (struct file * file, loff_t offset, int orig) {
 			case DEV393_MINOR(DEV393_EXIF_META1):
 			case DEV393_MINOR(DEV393_EXIF_META2):
 			case DEV393_MINOR(DEV393_EXIF_META3):
-				file->f_pos=offset*sizeof(struct exif_dir_table_t);
+                fp= dir_find_tag (offset);
+                if (fp < 0) return -EOVERFLOW; // tag is not in the directory
+                file->f_pos=fp;
 				break;
             case DEV393_MINOR(DEV393_EXIF_METADIR):
-                   file->f_pos=offset*sizeof(struct exif_dir_table_t);
+                file->f_pos=offset*sizeof(struct exif_dir_table_t);
                 break;
 			case DEV393_MINOR(DEV393_EXIF_TIME):
 				switch (offset) {
@@ -602,8 +604,11 @@ ssize_t    exif_write  (struct file * file, const char * buf, size_t count, loff
 	char tmp[MAX_EXIF_SIZE]; //! Or is it possible to disable IRQ while copy_from_user()?
 	unsigned long flags;
 	int disabled_err=0;
+    dev_dbg(g_devfp_ptr,"minor=0x%x\n", p);
+
 	if ((*off+count)>maxsize) {
-	    dev_warn(g_devfp_ptr,"%s:%d: Data (0x%x) does not fit into 0x%x bytes\n",__FILE__,__LINE__, (int) (*off+count), maxsize);
+//	    dev_warn(g_devfp_ptr,"%s:%d: Data (0x%x) does not fit into 0x%x bytes\n",__FILE__,__LINE__, (int) (*off+count), maxsize);
+        dev_dbg(g_devfp_ptr,"Data (0x%x) does not fit into 0x%x bytes, minor = 0x%x\n",(int) (*off+count), maxsize, p);
 		return -EOVERFLOW;
 	}
 	switch (p) {

src/include/uapi/elphel/c313a.h

@@ -1652,7 +1652,7 @@ struct p_names_t {
 
 
 // make this structure common for sensors, add fields as needed
-struct sensor_t {
+struct __attribute__((__packed__)) sensor_t {
 // sensor constants
    unsigned long  imageWidth;     ///< nominal image width for final images
    unsigned long  imageHeight;    ///< nominal image height for final images
@@ -1789,7 +1789,7 @@ struct i2c_timing_t {
 
 #define GAMMA_SCALE_SHIFT     10  // when scaling - shift right by GAMMA_SCALE_SHIFT (treat scale as 6.10)
 #define GAMMA_SCLALE_1 ( 1 << GAMMA_SCALE_SHIFT )      // gamma scale 1.0 - 0x400
-struct gamma_stuct_t {
+struct __attribute__((__packed__)) gamma_stuct_t {
     union {
         unsigned long hash32; /// fully identifies current table
         struct {

src/include/uapi/elphel/exifa.h

@@ -43,7 +43,7 @@ or Rational or else. The generated Exif header copies that variable fileds on to
 
 The compressed data buffer is stored in "meta pages", one per frame 
 */
-struct exif_dir_table_t {
+struct __attribute__((__packed__)) exif_dir_table_t {
         union {
           unsigned long ltag;// tag group and tag combined
           struct {
@@ -112,13 +112,13 @@ struct exif_dir_table_t {
 //  array(0x9003,2,"2001:06:21 12:00:00","len"=> 20), //date/time original time created, always use 20 bytes (19 ."\0")
 //  array(0x9291,2,"0        ") //original time sub-second length=10  9 ."\0"
 ///move back to interframe_params_t?
-struct frame_exif_t {
+struct __attribute__((__packed__)) frame_exif_t {
           unsigned short meta_index;     //! index of the linked meta page
           unsigned short signffff;       //! should be 0xffff - it will be a signature that JPEG data was not overwritten
           unsigned long  frame_length;   //! frame length
 };
 
-struct meta_GPSInfo_t {
+struct __attribute__((__packed__)) meta_GPSInfo_t {
    unsigned char GPSLatitudeRef; //"N"/"S"
    unsigned long GPSLatitude_deg_nom;
    unsigned long GPSLatitude_deg_denom;
@@ -142,7 +142,7 @@ struct meta_GPSInfo_t {
    unsigned char GPSMeasureMode;
 };
 //hack - use
-struct meta_CompassInfo_t {
+struct __attribute__((__packed__)) meta_CompassInfo_t {
 //   unsigned char GPSImgDirectionRef; //"M"/"T" //0x10
    unsigned long CompassDirection_nom; //0x11
    unsigned long CompassDirection_denom;

src/patches/README

 Patches from this directory are applied by 'meta-elphel393/recipes-kernel/linux/linux-xlnx' bitbake recipe. To add a new patch, append SRC_URI variable in the recipe.
+Short description of the paches:
+
+libata-eh.c.patch
+	This patch is a workaround for the situation when ESATA disk connection leads to kernel panic. Consider the following execution path in driver: libata-core.c:ata_exec_internal_sg -> error during command execution leading to command timeout -> libata-core.c:ata_qc_complete (or ata_port_freeze and finally to the same function) -> libata-core.c:ata_qc_schedule_eh where qc->scsicmd is a NULL pointer by the moment. This patch may not be needed when all hardware/software issues are rectified.

src/patches/libata-eh.c.patch

+diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
+index d2029a4..3fdf705 100644
+--- a/drivers/ata/libata-eh.c
++++ b/drivers/ata/libata-eh.c
+@@ -968,7 +968,7 @@ static void ata_eh_set_pending(struct ata_port *ap, int fastdrain)
+ void ata_qc_schedule_eh(struct ata_queued_cmd *qc)
+ {
+ 	struct ata_port *ap = qc->ap;
+-	struct request_queue *q = qc->scsicmd->device->request_queue;
++	struct request_queue *q;
+ 	unsigned long flags;
+ 
+ 	WARN_ON(!ap->ops->error_handler);
+@@ -981,9 +981,12 @@ void ata_qc_schedule_eh(struct ata_queued_cmd *qc)
+ 	 * Note that ATA_QCFLAG_FAILED is unconditionally set after
+ 	 * this function completes.
+ 	 */
+-	spin_lock_irqsave(q->queue_lock, flags);
+-	blk_abort_request(qc->scsicmd->request);
+-	spin_unlock_irqrestore(q->queue_lock, flags);
++	if (qc->scsicmd != NULL) {
++		q = qc->scsicmd->device->request_queue;
++		spin_lock_irqsave(q->queue_lock, flags);
++		blk_abort_request(qc->scsicmd->request);
++		spin_unlock_irqrestore(q->queue_lock, flags);
++	}
+ }
+ 
+ /**