Hello. On 10-05-2012 8:17, Thang Q. Nguyen wrote:
Signed-off-by: Thang Q. Nguyen<tqnguyen@xxxxxxx> --- drivers/ata/sata_dwc_460ex.c | 64 ++++++++++++++++++++++++++++++++++++++++-- 1 files changed, 61 insertions(+), 3 deletions(-)
diff --git a/drivers/ata/sata_dwc_460ex.c b/drivers/ata/sata_dwc_460ex.c index 937aeb3..6175e01 100755 --- a/drivers/ata/sata_dwc_460ex.c +++ b/drivers/ata/sata_dwc_460ex.c
[...]
@@ -1385,6 +1389,58 @@ static void sata_dwc_port_stop(struct ata_port *ap) ap->private_data = NULL; } +/** + * sata_dwc_check_atapi_dma - Filter ATAPI cmds which are unsuitable for DMA. + * @qc: queued command to check for chipset/DMA compatibility. + * + * The bmdma engines cannot handle speculative data sizes (bytecount + * under/over flow). So only allow DMA for data transfer commands with + * known data sizes. + */ +static int sata_dwc_check_atapi_dma(struct ata_queued_cmd *qc) +{
[...]
+ + /* -45150 (FFFF4FA2) to -1 (FFFFFFFF) shall use PIO mode */
Sector numbers are unsigned entities.
+ if (scmd->cmnd[0] == WRITE_10) { + lba = (scmd->cmnd[2] << 24) | + (scmd->cmnd[3] << 16) | + (scmd->cmnd[4] << 8) | + scmd->cmnd[5]; + if (lba>= 0xFFFF4FA2) + pio = 1; + } + /* + * WORK AROUND: Fix DMA issue when blank CD/DVD disc in the drive + * and user use the 'fdisk -l' command. No DMA data returned so + * we can not complete the QC.
The user shouldn't use 'fdisk' command on CD/DVD disks. On the other hand, he could use something like 'hdparm -t' od 'dd' with offset in which case I'm not sure this heuristics will work.
+ */ + else if (scmd->cmnd[0] == READ_10) { + lba = (scmd->cmnd[2] << 24) | + (scmd->cmnd[3] << 16) | + (scmd->cmnd[4] << 8) | + scmd->cmnd[5]; + if (lba < 0x20) + pio = 1; + } + } + return pio; +} + /* * Function : sata_dwc_exec_command_by_tag * arguments : ata_port *ap, ata_taskfile *tf, u8 tag, u32 cmd_issued
WBR, Sergei -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html