b50102d3e9
Based on original implementation from Jiangbi Liu and Maciej Trela. ATAPI transfers happen in two-to-three stages. The two stage atapi commands are those that include a dma data transfer. The data transfer portion of these operations is handled by the hardware packet-dma acceleration. The three-stage commands do not have a data transfer and are handled without hardware assistance in raw frame mode. stage1: transmit host-to-device fis to notify the device of an incoming atapi cdb. Upon reception of the pio-setup-fis repost the task_context to perform the dma transfer of the cdb+data (go to stage3), or repost the task_context to transmit the cdb as a raw frame (go to stage 2). stage2: wait for hardware notification of the cdb transmission and then go to stage 3. stage3: wait for the arrival of the terminating device-to-host fis and terminate the command. To keep the implementation simple we only support ATAPI packet-dma protocol (for commands with data) to avoid needing to handle the data transfer manually (like we do for SATA-PIO). This may affect compatibility for a small number of devices (see ATA_HORKAGE_ATAPI_MOD16_DMA). If the data-transfer underruns, or encounters an error the device-to-host fis is expected to arrive in the unsolicited frame queue to pass to libata for disposition. However, in the DONE_UNEXP_FIS (data underrun) case it appears we need to craft a response. In the DONE_REG_ERR case we do receive the UF and propagate it to libsas. Signed-off-by: Maciej Trela <maciej.trela@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com> |
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| .. | ||
| acpi | ||
| asm-generic | ||
| crypto | ||
| drm | ||
| keys | ||
| linux | ||
| math-emu | ||
| media | ||
| mtd | ||
| net | ||
| pcmcia | ||
| rdma | ||
| rxrpc | ||
| scsi | ||
| sound | ||
| target | ||
| trace | ||
| video | ||
| xen | ||
| Kbuild | ||