kernel/git/stable/linux.git/drivers/ata/libata-pmp.c, branch linux-7.2.y

ata: libata-pmp: add JMicron JMS562 quirk

2026-06-10T09:39:37+00:00

JMicron JMS562, as used in QNAP QDA-A2AR RAID1 adapters, may keep the exported ATA device not ready while the array is rebuilding. In this state, libata may repeatedly try to softreset and classify the fan-out link. On the affected adapter, this can time out, make PMP/SCR access fail, and eventually disable the fan-out link before the RAID volume is exported. A failing boot shows the fan-out link failing SRST, PMP access timing out, SCR read failing, and the link being disabled: ata4.00: softreset failed (device not ready) ata4.15: qc timeout after 3000 msecs (cmd 0xe4) ata4.00: failed to read SCR 0 (Emask=0x4) ata4.00: failed to recover link after 3 tries, disabling After that, the root filesystem on the exported RAID volume cannot be found. Add JMS562 to the existing JMicron PMP quirk that disables LPM, avoids softreset on fan-out links, and assumes an ATA device. This prevents libata from dropping the exported RAID volume during rebuild recovery. Signed-off-by: Xu Rao Reviewed-by: Damien Le Moal 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

ata: libata-scsi: do not needlessly defer commands when using PMP with FBS

2026-05-18T10:26:51+00:00

The ACS specification does not allow a non-NCQ command to be issued while an NCQ command is outstanding. Commit 0ea84089dbf6 ("ata: libata-scsi: avoid Non-NCQ command starvation") introduced a feature where a deferred non-NCQ command gets issued from a workqueue. The design stores a single non-NCQ command per port. However, when using Port Multipliers (PMPs), specifically PMPs that support FIS-Based Switching (FBS), non-NCQ and NCQ commands can be mixed on the same port, just not for the same link, see e.g. ata_std_qc_defer() which is, and always has operated on a per-link basis. Therefore, move the deferred_qc from struct ata_port to struct ata_link. This way, when using a PMP with FBS, we will not needlessly defer commands to all other links, just because one link issued a non-NCQ command while having an NCQ command outstanding. Only commands for that specific link will be deferred. This is in line with how PMPs with FBS worked before commit 0ea84089dbf6 ("ata: libata-scsi: avoid Non-NCQ command starvation"). Fixes: 0ea84089dbf6 ("ata: libata-scsi: avoid Non-NCQ command starvation") Tested-by: Tommy Kelly Reviewed-by: Damien Le Moal Signed-off-by: Niklas Cassel

ata: libata-scsi: do not use the deferred QC feature on PMPs with CBS

2026-05-18T10:25:28+00:00

When using Port Multipliers (PMPs) with Command-Based Switching (CBS), you can only issue commands to one link at a time. For PMPs with CBS, there is already code to handle commands being sent to different links in sata_pmp_qc_defer_cmd_switch() using ap->excl_link. sata_sil24 also makes use of ap->excl_link. A user on the list reported that commit 0ea84089dbf6 ("ata: libata-scsi: avoid Non-NCQ command starvation") broke PMPs with CBS. The commit introduced code that stores a deferred qc in ap->deferred_qc, to later be issued via a workqueue. It turns out that this change is incompatible with the existing ap->excl_link handling used by PMPs with CBS. Thus, modify sata_pmp_qc_defer_cmd_switch() and sil24_qc_defer() to return ATA_DEFER_LINK_EXCL, and make sure that the deferred QC handling via workqueue is not used for this return value. This way, PMPs with CBS will work once again. Note that the starvation referenced in commit 0ea84089dbf6 ("ata: libata-scsi: avoid Non-NCQ command starvation") can only happen on libsas ports, and libsas does not support Port Multipliers, thus there is no harm of reverting back to the previous way of deferring commands for PMPs with CBS. Non-libsas ports connected to anything but a PMP with CBS (e.g. a normal drive or a PMP with FBS) will continue using the deferred workqueue, since it does result in lower completion latencies for non-NCQ commands, even though the workqueue is not strictly needed to avoid starvation for non-libsas ports. If we want to modify the scope of the workqueue issuing to also handle PMPs with CBS, then we should ensure that we can save both NCQ and non-NCQ commands in ap->deferred_qc, while also removing the existing PMP CBS handling using ap->excl_link, such that we don't duplicate features. While at it, also add a comment explaining how the ap->excl_link mechanism works. Fixes: 0ea84089dbf6 ("ata: libata-scsi: avoid Non-NCQ command starvation") Tested-by: Tommy Kelly Reported-by: Tommy Kelly Closes: https://lore.kernel.org/linux-ide/ce09cc21-a8e9-4845-b205-35411e22fba9@tkel.ly/ Reviewed-by: Damien Le Moal Signed-off-by: Niklas Cassel

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

ata: libata-eh: Simplify reset operation management

2025-07-16T07:31:43+00:00

Introduce struct ata_reset_operations to aggregate in a single structure the definitions of the 4 reset methods (prereset, softreset, hardreset and postreset) for a port. This new structure is used in struct ata_port to define the reset methods for a regular port (reset field) and for a port-multiplier port (pmp_reset field). A pointer to either of these fields replaces the 4 reset method arguments passed to ata_eh_recover() and ata_eh_reset(). The definition of the reset methods for all drivers is changed to use the reset and pmp_reset fields in struct ata_port_operations. A large number of files is modifed, but no functional changes are introduced. Suggested-by: Niklas Cassel Signed-off-by: Damien Le Moal Reviewed-by: Niklas Cassel Reviewed-by: Martin K. Petersen Reviewed-by: Hannes Reinecke Link: https://lore.kernel.org/r/20250716020315.235457-3-dlemoal@kernel.org Signed-off-by: Niklas Cassel

ata: libata: Move sector_buf from struct ata_port to struct ata_device

2024-09-07T01:16:55+00:00

The 512B buffer sector_buf field of struct ata_port is used for scanning devices as well as during error recovery with ata EH. This buffer is thus useless if a port does not have a device connected to it. And also given that commands using this buffer are issued to devices, and not to ports, move this buffer definition from struct ata_port to struct ata_device. This change slightly increases system memory usage for systems using a port-multiplier as in that case we do not need a per-device buffer for scanning devices (PMP does not allow parallel scanning) nor for EH (as when entering EH we are guaranteed that all commands to all devices connected to the PMP have completed or have been aborted). However, this change reduces memory usage on systems that have many ports with only few devices rives connected, which is a much more common use case than the PMP use case. Suggested-by: Niklas Cassel Signed-off-by: Damien Le Moal Reviewed-by: Hannes Reinecke Reviewed-by: Niklas Cassel

ata: libata: add tracepoints for ATA error handling

2022-01-05T10:33:01+00:00

Add tracepoints for ATA error handling. Signed-off-by: Hannes Reinecke Signed-off-by: Damien Le Moal

ata: libata-pmp: Fix misspelling of 'val'

2021-03-12T14:28:30+00:00

Fixes the following W=1 kernel build warning(s): drivers/ata/libata-pmp.c:76: warning: Function parameter or member 'val' not described in 'sata_pmp_write' drivers/ata/libata-pmp.c:76: warning: Excess function parameter 'r_val' description in 'sata_pmp_write' Cc: Jens Axboe Cc: Tejun Heo Cc: linux-ide@vger.kernel.org Signed-off-by: Lee Jones Signed-off-by: Jens Axboe