[SCSI] areca: improve driver stability and compatibility

Description:

    1. Implement PCI-Express error recovery function and AER
       capability, especially thanks to Yanmin Zhang's openhanded help
       about AER

    2. Implement the selection of ARCMSR_MAX_XFER_SECTORS_B=4096 if
       firmware version is latter than 1.42

    3. Add arcmsr_done4_abort_postqueue in arcmsr_iop_reset function
       to improve the stability as hot-unplug/plug

    4. Modify the ISR, arcmsr_interrupt routine, to prevent the
       inconsistency with sg_mod driver if application directly calls
       the arcmsr driver w/o passing through scsi midlayer
Signed-off-by: Nick Cheng <nick.cheng@areca.com.tw>
[jejb: unused variable removal]
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/arcmsr/arcmsr.h

@@ -48,9 +48,10 @@ struct class_device_attribute;
 
 #define ARCMSR_MAX_OUTSTANDING_CMD 						256
 #define ARCMSR_MAX_FREECCB_NUM							288
-#define ARCMSR_DRIVER_VERSION				"Driver Version 1.20.00.13"
+#define ARCMSR_DRIVER_VERSION				"Driver Version 1.20.00.14"
 #define ARCMSR_SCSI_INITIATOR_ID						255
 #define ARCMSR_MAX_XFER_SECTORS							512
+#define ARCMSR_MAX_XFER_SECTORS_B                                              4096
 #define ARCMSR_MAX_TARGETID							 17
 #define ARCMSR_MAX_TARGETLUN							  8
 #define ARCMSR_MAX_CMD_PERLUN				 ARCMSR_MAX_OUTSTANDING_CMD
@@ -469,4 +470,3 @@ extern void arcmsr_post_Qbuffer(struct AdapterControlBlock *acb);
 extern struct class_device_attribute *arcmsr_host_attrs[];
 extern int arcmsr_alloc_sysfs_attr(struct AdapterControlBlock *acb);
 void arcmsr_free_sysfs_attr(struct AdapterControlBlock *acb);
-