diff options
Diffstat (limited to 'drivers/usb/storage/scsiglue.c')
| -rw-r--r-- | drivers/usb/storage/scsiglue.c | 40 |
1 files changed, 27 insertions, 13 deletions
diff --git a/drivers/usb/storage/scsiglue.c b/drivers/usb/storage/scsiglue.c index 1ba19eaa1970..8c1e2954f3b9 100644 --- a/drivers/usb/storage/scsiglue.c +++ b/drivers/usb/storage/scsiglue.c @@ -81,6 +81,16 @@ static int slave_alloc (struct scsi_device *sdev) */ sdev->inquiry_len = 36; + /* Scatter-gather buffers (all but the last) must have a length + * divisible by the bulk maxpacket size. Otherwise a data packet + * would end up being short, causing a premature end to the data + * transfer. Since high-speed bulk pipes have a maxpacket size + * of 512, we'll use that as the scsi device queue's DMA alignment + * mask. Guaranteeing proper alignment of the first buffer will + * have the desired effect because, except at the beginning and + * the end, scatter-gather buffers follow page boundaries. */ + blk_queue_update_dma_alignment(sdev->request_queue, (512 - 1)); + /* * The UFI spec treates the Peripheral Qualifier bits in an * INQUIRY result as reserved and requires devices to set them @@ -100,23 +110,19 @@ static int slave_configure(struct scsi_device *sdev) { struct us_data *us = host_to_us(sdev->host); - /* Scatter-gather buffers (all but the last) must have a length - * divisible by the bulk maxpacket size. Otherwise a data packet - * would end up being short, causing a premature end to the data - * transfer. Since high-speed bulk pipes have a maxpacket size - * of 512, we'll use that as the scsi device queue's DMA alignment - * mask. Guaranteeing proper alignment of the first buffer will - * have the desired effect because, except at the beginning and - * the end, scatter-gather buffers follow page boundaries. */ - blk_queue_dma_alignment(sdev->request_queue, (512 - 1)); - /* Many devices have trouble transfering more than 32KB at a time, * while others have trouble with more than 64K. At this time we * are limiting both to 32K (64 sectores). */ - if ((us->flags & US_FL_MAX_SECTORS_64) && - sdev->request_queue->max_sectors > 64) - blk_queue_max_sectors(sdev->request_queue, 64); + if (us->flags & (US_FL_MAX_SECTORS_64 | US_FL_MAX_SECTORS_MIN)) { + unsigned int max_sectors = 64; + + if (us->flags & US_FL_MAX_SECTORS_MIN) + max_sectors = PAGE_CACHE_SIZE >> 9; + if (sdev->request_queue->max_sectors > max_sectors) + blk_queue_max_sectors(sdev->request_queue, + max_sectors); + } /* We can't put these settings in slave_alloc() because that gets * called before the device type is known. Consequently these @@ -177,6 +183,14 @@ static int slave_configure(struct scsi_device *sdev) * is an occasional series of retries that will all fail. */ sdev->retry_hwerror = 1; + /* USB disks should allow restart. Some drives spin down + * automatically, requiring a START-STOP UNIT command. */ + sdev->allow_restart = 1; + + /* Some USB cardreaders have trouble reading an sdcard's last + * sector in a larger then 1 sector read, since the performance + * impact is negible we set this flag for all USB disks */ + sdev->last_sector_bug = 1; } else { /* Non-disk-type devices don't need to blacklist any pages |