Robert Hancock wrote: > This patch is based on an original patch from Kuan Luo of NVIDIA, > posted under subject "fixed a bug of adma in rhel4u5 with HDS7250SASUN500G". > His description follows. I've reworked it a bit to avoid some unnecessary > repeated checks but it should be functionally identical. > > "The patch is to solve the error message "ata1: CPB flags CMD err, > flags=0x11" when testing HDS7250SASUN500G in rhel4u5. > I tested this hd in 2.6.24-rc7 which needed to remove the mask in > blacklist to run the ncq and the same error also showed up. > > I traced the bug and found that the interrupt finished a command (for > example, tag=0) when the driver got that adma status is > NV_ADMA_STAT_DONE and cpb->resp_flags is NV_CPB_RESP_DONE. > However, For this hd, the drive maybe didn't clear bit 0 at this moment. > It meaned the hardware had not completely finished the command. > If at the same time the driver freed the command(tag 0) and sended > another command (tag 0), the error happened. > > The notifier register is 32-bit register containing notifier value. > Value is bit vector containing one bit per tag number (0-31) in > corresponding bit positions (bit 0 is for tag 0, etc). When bit is set > then ADMA indicates that command with corresponding tag number completed > execution. > > So i added the check notifier code. Sometimes i saw that the notifier > reg set some bits , but the adma status set NV_ADMA_STAT_CMD_COMPLETE > ,not NV_ADMA_STAT_DONE. So i added the NV_ADMA_STAT_CMD_COMPLETE check > code." > > Signed-off-by: Robert Hancock <hancockr@xxxxxxx> Any chance this fixes the FLUSH problem? -- tejun - 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
