kernel/linux.git/drivers/ata/libata.h, branch v7.2-rc1

ata: Annotate functions in the issuing path with __must_hold()

2026-06-01T17:14:41+00:00

Annotate the following functions used in the issuing path: ata_qc_issue(), ata_sas_queuecmd(), ata_scsi_qc_issue(), ata_scsi_translate(), __ata_scsi_queuecmd() These functions are all used in the issuing path, so context analysis will be able to verify that the ap lock is held, from it is taken in sas_queuecommand() or ata_scsi_queuecmd() all the way down to ata_qc_issue(). Commenting out the spin_lock_irqsave() successfully results in a compiler error on Clang 23. Signed-off-by: Bart Van Assche Co-developed-by: Niklas Cassel Reviewed-by: Hannes Reinecke Signed-off-by: Niklas Cassel

ata: libata: Pass ap parameter directly to functions in the issuing path

2026-06-01T17:14:29+00:00

Context analysis cannot recognize that qc->ap == ap. Therefore, grow a struct ata_port parameter to the following functions: ata_qc_issue(), __ata_scsi_queuecmd(), and ata_scsi_translate() such that we will be able to enable context analysis in a follow-up commit. No functionality has been changed. Signed-off-by: Bart Van Assche Reviewed-by: Hannes Reinecke Signed-off-by: Niklas Cassel

ata: libata: Document when host->eh_mutex should be held

2026-06-01T17:09:08+00:00

Annotate the following functions with __must_hold(&host->eh_mutex): * All ata_port_operations.error_handler() implementations. * ata_eh_reset() and ata_eh_recover() because these functions call ata_eh_release() and ata_eh_acquire(). * All callers of ata_eh_reset() and ata_eh_recover(). Enable Clang's context analysis. This will cause the build to fail if e.g. a locking bug would be introduced in an error path. This patch should not affect the generated assembler code. Signed-off-by: Bart Van Assche [cassel: drop note about clang 23 from commit log] Signed-off-by: Niklas Cassel

ata: libata: Add an argument to ata_eh_reset()

2026-06-01T17:09:07+00:00

Pass the ATA port pointer as first argument to ata_eh_reset(). No functionality has been changed. This patch prepares for enabling lock context analysis. Without this patch, lockdep_assert_held() statements would have to be added before each ata_eh_reset() call because the compiler doesn't know that ap->link.p == ap. See also ata_link_init(). Signed-off-by: Bart Van Assche Signed-off-by: Niklas Cassel

Merge tag 'ata-6.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/libata/linux

2026-02-13T01:12:43+00:00

Pull ATA updates from Damien Le Moal: - Cleanup IRQ masking in the handling of completed report zones commands (Niklas) - Improve the handling of Thunderbolt attached devices to speed up device removal (Henry) - Several patches to generalize the existing max_sec quirks to facilitates quirking the maximum command size of buggy drives, many of which have recently showed up with the recent increase of the default max_sectors block limit (Niklas) - Cleanup the ahci-platform and sata dt-bindings schema (Rob, Manivannan) - Improve device node scan in the ahci-dwc driver (Krzysztof) - Remove clang W=1 warnings with the ahci-imx and ahci-xgene drivers (Krzysztof) - Fix a long standing potential command starvation situation with non-NCQ commands issued when NCQ commands are on-going (me) - Limit max_sectors to 8191 on the INTEL SSDSC2KG480G8 SSD (Niklas) - Remove Vesa Local Bus (VLB) support in the pata_legacy driver (Ethan) - Simple fixes in the pata_cypress (typo) and pata_ftide010 (timing) drivers (Ethan, Linus W) * tag 'ata-6.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/libata/linux: ata: pata_ftide010: Fix some DMA timings ata: pata_cypress: fix typo in error message ata: pata_legacy: remove VLB support ata: libata-core: Quirk INTEL SSDSC2KG480G8 max_sectors dt-bindings: ata: sata: Document the graph port ata: libata-scsi: avoid Non-NCQ command starvation ata: libata-scsi: refactor ata_scsi_translate() ata: ahci-xgene: Fix Wvoid-pointer-to-enum-cast warning ata: ahci-imx: Fix Wvoid-pointer-to-enum-cast warning ata: ahci-dwc: Simplify with scoped for each OF child loop dt-bindings: ata: ahci-platform: Drop unnecessary select schema ata: libata: Allow more quirks ata: libata: Add libata.force parameter max_sec ata: libata: Add support to parse equal sign in libata.force ata: libata: Change libata.force to use the generic ATA_QUIRK_MAX_SEC quirk ata: libata: Add ata_force_get_fe_for_dev() helper ata: libata: Add ATA_QUIRK_MAX_SEC and convert all device quirks ata: libata: avoid long timeouts on hot-unplugged SATA DAS ata: libata-scsi: Remove superfluous local_irq_save()

scsi: Change the return type of the .queuecommand() callback

2026-01-24T02:32:34+00:00

In clang version 21.1 and later the -Wimplicit-enum-enum-cast warning option has been introduced. This warning is enabled by default and can be used to catch .queuecommand() implementations that return another value than 0 or one of the SCSI_MLQUEUE_* constants. Hence this patch that changes the return type of the .queuecommand() implementations from 'int' into 'enum scsi_qc_status'. No functionality has been changed. Cc: Damien Le Moal Cc: John Garry Signed-off-by: Bart Van Assche Link: https://patch.msgid.link/20260115210357.2501991-6-bvanassche@acm.org Signed-off-by: Martin K. Petersen

ata: libata-scsi: avoid Non-NCQ command starvation

2026-01-14T10:07:14+00:00

When a non-NCQ command is issued while NCQ commands are being executed, ata_scsi_qc_issue() indicates to the SCSI layer that the command issuing should be deferred by returning SCSI_MLQUEUE_XXX_BUSY. This command deferring is correct and as mandated by the ACS specifications since NCQ and non-NCQ commands cannot be mixed. However, in the case of a host adapter using multiple submission queues, when the target device is under a constant load of NCQ commands, there are no guarantees that requeueing the non-NCQ command will be executed later and it may be deferred again repeatedly as other submission queues can constantly issue NCQ commands from different CPUs ahead of the non-NCQ command. This can lead to very long delays for the execution of non-NCQ commands, and even complete starvation for these commands in the worst case scenario. Since the block layer and the SCSI layer do not distinguish between queueable (NCQ) and non queueable (non-NCQ) commands, libata-scsi SAT implementation must ensure forward progress for non-NCQ commands in the presence of NCQ command traffic. This is similar to what SAS HBAs with a hardware/firmware based SAT implementation do. Implement such forward progress guarantee by limiting requeueing of non-NCQ commands from ata_scsi_qc_issue(): when a non-NCQ command is received and NCQ commands are in-flight, do not force a requeue of the non-NCQ command by returning SCSI_MLQUEUE_XXX_BUSY and instead return 0 to indicate that the command was accepted but hold on to the qc using the new deferred_qc field of struct ata_port. This deferred qc will be issued using the work item deferred_qc_work running the function ata_scsi_deferred_qc_work() once all in-flight commands complete, which is checked with the port qc_defer() callback return value indicating that no further delay is necessary. This check is done using the helper function ata_scsi_schedule_deferred_qc() which is called from ata_scsi_qc_complete(). This thus excludes this mechanism from all internal non-NCQ commands issued by ATA EH. When a port deferred_qc is non NULL, that is, the port has a command waiting for the device queue to drain, the issuing of all incoming commands (both NCQ and non-NCQ) is deferred using the regular busy mechanism. This simplifies the code and also avoids potential denial of service problems if a user issues too many non-NCQ commands. Finally, whenever ata EH is scheduled, regardless of the reason, a deferred qc is always requeued so that it can be retried once EH completes. This is done by calling the function ata_scsi_requeue_deferred_qc() from ata_eh_set_pending(). This avoids the need for any special processing for the deferred qc in case of NCQ error, link or device reset, or device timeout. Reported-by: Xingui Yang Reported-by: Igor Pylypiv Fixes: bdb01301f3ea ("scsi: Add host and host template flag 'host_tagset'") Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal Reviewed-by: Niklas Cassel Reviewed-by: Martin K. Petersen Reviewed-by: John Garry Tested-by: Igor Pylypiv Tested-by: Xingui Yang

ata: libata: avoid long timeouts on hot-unplugged SATA DAS

2025-12-15T07:32:05+00:00

When a SATA DAS enclosure is connected behind a Thunderbolt PCIe switch, hot-unplugging the whole enclosure causes pciehp to tear down the PCI hierarchy before the SCSI layer issues SYNCHRONIZE CACHE and START STOP UNIT for the disks. libata still queues these commands and the AHCI driver tries to access the HBA registers even though the PCI channel is already offline. This results in a series of timeouts and error recovery attempts, e.g.: [ 824.778346] pcieport 0000:00:07.0: pciehp: Slot(14): Link Down [ 891.612720] ata8.00: qc timeout after 5000 msecs (cmd 0xec) [ 902.876501] ata8.00: qc timeout after 10000 msecs (cmd 0xec) [ 934.107998] ata8.00: qc timeout after 30000 msecs (cmd 0xec) [ 936.206431] sd 7:0:0:0: [sda] Synchronize Cache(10) failed: Result: hostbyte=DID_BAD_TARGET driverbyte=DRIVER_OK ... [ 1006.298356] ata1.00: qc timeout after 5000 msecs (cmd 0xec) [ 1017.561926] ata1.00: qc timeout after 10000 msecs (cmd 0xec) [ 1048.791790] ata1.00: qc timeout after 30000 msecs (cmd 0xec) [ 1050.890035] sd 0:0:0:0: [sdb] Synchronize Cache(10) failed: Result: hostbyte=DID_BAD_TARGET driverbyte=DRIVER_OK With this patch applied, the same hot-unplug looks like: [ 59.965496] pcieport 0000:00:07.0: pciehp: Slot(14): Link Down [ 60.002502] sd 7:0:0:0: [sda] Synchronize Cache(10) failed: Result: hostbyte=DID_BAD_TARGET driverbyte=DRIVER_OK ... [ 60.103050] sd 0:0:0:0: [sdb] Synchronize Cache(10) failed: Result: hostbyte=DID_BAD_TARGET driverbyte=DRIVER_OK In this test setup with two disks, the hot-unplug sequence shrinks from about 226 seconds (~3.8 minutes) between the Link Down event and the last SYNCHRONIZE CACHE failure to under a second. Without this patch the total delay grows roughly with the number of disks, because each disk gets its own SYNCHRONIZE CACHE and qc timeout series. If the underlying PCI device is already gone, these commands cannot succeed anyway. Avoid issuing them by introducing ata_adapter_is_online(), which checks pci_channel_offline() for PCI-based hosts. It is used from ata_scsi_find_dev() to return NULL, causing the SCSI layer to fail new commands with DID_BAD_TARGET immediately, and from ata_qc_issue() to bail out before touching the HBA registers. Since such failures would otherwise trigger libata error handling, ata_adapter_is_online() is also consulted from ata_scsi_port_error_handler(). When the adapter is offline, libata skips ap->ops->error_handler(ap) and completes error handling using the existing path, rather than running a full EH sequence against a dead adapter. With this change, SYNCHRONIZE CACHE and START STOP UNIT commands issued during hot-unplug fail quickly once the PCI channel is offline, without qc timeout spam or long libata EH delays. Suggested-by: Damien Le Moal Signed-off-by: Henry Tseng Signed-off-by: Damien Le Moal

scsi: ata: Stop disk on restart if ACPI power resources are found

2025-11-08T18:24:56+00:00

Some embedded devices have the ability to control whether power is provided to the disks via the SATA power connector or not. ACPI power resources are usually off by default, thus making it unclear if the specific power resource will retain its state after a restart. If power resources are defined on ATA ports / devices in ACPI, we should stop the disk on SYSTEM_RESTART, to ensure the disk will not lose power while active. Add a new function, ata_acpi_dev_manage_restart(), that will be used to determine if a disk should be stopped before restarting the system. If a usable ACPI power resource has been found, it is assumed that the disk will lose power after a restart and should be stopped to avoid unclean shutdown due to power loss. Reviewed-by: Damien Le Moal Signed-off-by: Markus Probst Link: https://patch.msgid.link/20251104142413.322347-4-markus.probst@posteo.de Signed-off-by: Martin K. Petersen

scsi: ata: Use ACPI methods to power on disks

2025-11-08T18:24:55+00:00

Some embedded devices have the ability to control whether power is provided to the disks via the SATA power connector or not. If power resources are defined on ATA ports / devices in ACPI, we should try to set the power state to D0 before probing the disk to ensure that any power supply or power gate that may exist is providing power to the disk. An example for such devices would be newer synology NAS devices. Every disk slot has its own SATA power connector. Whether the connector is providing power is controlled via an gpio, which is *off by default*. Also the disk loses power on reboots. Add a new function, ata_acpi_port_power_on(), that will be used to power on the SATA power connector if usable ACPI power resources on the associated ATA port / device are found. It will be called right before probing the port, therefore the disk will be powered on just in time. Signed-off-by: Markus Probst Reviewed-by: Damien Le Moal Link: https://patch.msgid.link/20251104142413.322347-3-markus.probst@posteo.de Signed-off-by: Martin K. Petersen