硬盘第一次读写过慢问题

内核打印如下：

08-03-11-09-39--scsi 5:0:0:0: Direct-Access ARRIS Portable PVR HDD 1A02 PQ: 0 ANSI: 6
08-03-11-09-39--sd 5:0:0:0: [sdd] 976773168 512-byte logical blocks: (500 GB/465 GiB)
08-03-11-09-39--sd 5:0:0:0: [sdd] Write Protect is off
08-03-11-09-39--sd 5:0:0:0: [sdd] Mode Sense: 43 00 00 00
08-03-11-09-39--sd 5:0:0:0: Attached scsi generic sg0 type 0
08-03-11-09-39--sd 5:0:0:0: [sdd] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA
08-03-11-09-39-- sdd: sdd1
08-03-11-09-39--sd 5:0:0:0: [sdd] Attached SCSI disk

 

修改方法：

测试电压正常，就是第一次读写很慢，切有“usb 2-1: reset high-speed USB device number 4 using ehci-brcm”打印。

更新硬盘转接板后该问题就不存在了