pwm: atmel-hlcdc: Fix frequency output being half of expected#6
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kay54068 wants to merge 1 commit intolinux4microchip:linux-6.12-mchpfrom
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pwm: atmel-hlcdc: Fix frequency output being half of expected#6kay54068 wants to merge 1 commit intolinux4microchip:linux-6.12-mchpfrom
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The atmel-hlcdc PWM driver generates an output frequency that is exactly half of the value requested in the device tree. For example, a request for 1000 Hz results in a 500 Hz output. This is caused by an incorrect prescaler calculation. The driver's formula for the clock divider did not match the hardware, which uses a division factor of 2^(pres + 1). The driver was missing the "+1", causing the output period to be doubled. This patch corrects the calculation to `2^(pres + 1)`, aligning it with the hardware's behavior and ensuring the generated frequency is correct.
cristibirsan
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[ Upstream commit 2939203 ] In the current implementation, the enetc_xdp_xmit() always transmits redirected XDP frames even if the link is down, but the frames cannot be transmitted from TX BD rings when the link is down, so the frames are still kept in the TX BD rings. If the XDP program is uninstalled, users will see the following warning logs. fsl_enetc 0000:00:00.0 eno0: timeout for tx ring #6 clear More worse, the TX BD ring cannot work properly anymore, because the HW PIR and CIR are not equal after the re-initialization of the TX BD ring. At this point, the BDs between CIR and PIR are invalid, which will cause a hardware malfunction. Another reason is that there is internal context in the ring prefetch logic that will retain the state from the first incarnation of the ring and continue prefetching from the stale location when we re-initialize the ring. The internal context is only reset by an FLR. That is to say, for LS1028A ENETC, software cannot set the HW CIR and PIR when initializing the TX BD ring. It does not make sense to transmit redirected XDP frames when the link is down. Add a link status check to prevent transmission in this condition. This fixes part of the issue, but more complex cases remain. For example, the TX BD ring may still contain unsent frames when the link goes down. Those situations require additional patches, which will build on this one. Fixes: 9d2b68c ("net: enetc: add support for XDP_REDIRECT") Signed-off-by: Wei Fang <wei.fang@nxp.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Reviewed-by: Hariprasad Kelam <hkelam@marvell.com> Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com> Link: https://patch.msgid.link/20251211020919.121113-1-wei.fang@nxp.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
cristibirsan
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commit c943bfc upstream. After a copy pair swap the block device's "device" symlink points to the secondary CCW device, but the gendisk's parent remained the primary, leaving /sys/block/<dasdx> under the wrong parent. Move the gendisk to the secondary's device with device_move(), keeping the sysfs topology consistent after the swap. Fixes: 413862c ("s390/dasd: add copy pair swap capability") Cc: stable@vger.kernel.org #6.1 Reviewed-by: Jan Hoeppner <hoeppner@linux.ibm.com> Signed-off-by: Stefan Haberland <sth@linux.ibm.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
lranders
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[ Upstream commit d935187 ] A potential circular locking dependency (ABBA deadlock) exists between `ec_dev->lock` and the clock framework's `prepare_lock`. The first order (A -> B) occurs when scp_ipi_send() is called while `ec_dev->lock` is held (e.g., within cros_ec_cmd_xfer()): 1. cros_ec_cmd_xfer() acquires `ec_dev->lock` and calls scp_ipi_send(). 2. scp_ipi_send() calls clk_prepare_enable(), which acquires `prepare_lock`. See #0 in the following example calling trace. (Lock Order: `ec_dev->lock` -> `prepare_lock`) The reverse order (B -> A) is more complex and has been observed (learned) by lockdep. It involves the clock prepare operation triggering power domain changes, which then propagates through sysfs and power supply uevents, eventually calling back into the ChromeOS EC driver and attempting to acquire `ec_dev->lock`: 1. Something calls clk_prepare(), which acquires `prepare_lock`. It then triggers genpd operations like genpd_runtime_resume(), which takes `&genpd->mlock`. 2. Power domain changes can trigger regulator changes; regulator changes can then trigger device link changes; device link changes can then trigger sysfs changes. Eventually, power_supply_uevent() is called. 3. This leads to calls like cros_usbpd_charger_get_prop(), which calls cros_ec_cmd_xfer_status(), which then attempts to acquire `ec_dev->lock`. See linux4microchip#1 ~ linux4microchip#6 in the following example calling trace. (Lock Order: `prepare_lock` -> `&genpd->mlock` -> ... -> `&ec_dev->lock`) Move the clk_prepare()/clk_unprepare() operations for `scp->clk` to the remoteproc prepare()/unprepare() callbacks. This ensures `prepare_lock` is only acquired in prepare()/unprepare() callbacks. Since `ec_dev->lock` is not involved in the callbacks, the dependency loop is broken. This means the clock is always "prepared" when the SCP is running. The prolonged "prepared time" for the clock should be acceptable as SCP is designed to be a very power efficient processor. The power consumption impact can be negligible. A simplified calling trace reported by lockdep: > -> linux4microchip#6 (&ec_dev->lock) > cros_ec_cmd_xfer > cros_ec_cmd_xfer_status > cros_usbpd_charger_get_port_status > cros_usbpd_charger_get_prop > power_supply_get_property > power_supply_show_property > power_supply_uevent > dev_uevent > uevent_show > dev_attr_show > sysfs_kf_seq_show > kernfs_seq_show > -> linux4microchip#5 (kn->active#2) > kernfs_drain > __kernfs_remove > kernfs_remove_by_name_ns > sysfs_remove_file_ns > device_del > __device_link_del > device_links_driver_bound > -> linux4microchip#4 (device_links_lock) > device_link_remove > _regulator_put > regulator_put > -> linux4microchip#3 (regulator_list_mutex) > regulator_lock_dependent > regulator_disable > scpsys_power_off > _genpd_power_off > genpd_power_off > -> linux4microchip#2 (&genpd->mlock/1) > genpd_add_subdomain > pm_genpd_add_subdomain > scpsys_add_subdomain > scpsys_probe > -> linux4microchip#1 (&genpd->mlock) > genpd_runtime_resume > __rpm_callback > rpm_callback > rpm_resume > __pm_runtime_resume > clk_core_prepare > clk_prepare > -> #0 (prepare_lock) > clk_prepare > scp_ipi_send > scp_send_ipi > mtk_rpmsg_send > rpmsg_send > cros_ec_pkt_xfer_rpmsg Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org> Reviewed-by: Chen-Yu Tsai <wenst@chromium.org> Tested-by: Chen-Yu Tsai <wenst@chromium.org> Link: https://lore.kernel.org/r/20260112110755.2435899-1-tzungbi@kernel.org Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
lranders
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Apr 27, 2026
commit 1ac22c8 upstream. This leak will cause a hang when tearing down the SCSI host. For example, iscsid hangs with the following call trace: [130120.652718] scsi_alloc_sdev: Allocation failure during SCSI scanning, some SCSI devices might not be configured PID: 2528 TASK: ffff9d0408974e00 CPU: 3 COMMAND: "iscsid" #0 [ffffb5b9c134b9e0] __schedule at ffffffff860657d4 linux4microchip#1 [ffffb5b9c134ba28] schedule at ffffffff86065c6f linux4microchip#2 [ffffb5b9c134ba40] schedule_timeout at ffffffff86069fb0 linux4microchip#3 [ffffb5b9c134bab0] __wait_for_common at ffffffff8606674f linux4microchip#4 [ffffb5b9c134bb10] scsi_remove_host at ffffffff85bfe84b linux4microchip#5 [ffffb5b9c134bb30] iscsi_sw_tcp_session_destroy at ffffffffc03031c4 [iscsi_tcp] linux4microchip#6 [ffffb5b9c134bb48] iscsi_if_recv_msg at ffffffffc0292692 [scsi_transport_iscsi] linux4microchip#7 [ffffb5b9c134bb98] iscsi_if_rx at ffffffffc02929c2 [scsi_transport_iscsi] linux4microchip#8 [ffffb5b9c134bbf0] netlink_unicast at ffffffff85e551d6 #9 [ffffb5b9c134bc38] netlink_sendmsg at ffffffff85e554ef Fixes: 8fe4ce5 ("scsi: core: Fix a use-after-free") Cc: stable@vger.kernel.org Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> Reviewed-by: Mike Christie <michael.christie@oracle.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Link: https://patch.msgid.link/20260223232728.93350-1-junxiao.bi@oracle.com Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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The atmel-hlcdc PWM driver generates an output frequency that is
exactly half of the value requested in the device tree. For example,
a request for 1000 Hz results in a 500 Hz output.
This is caused by an incorrect prescaler calculation. The driver's
formula for the clock divider did not match the hardware, which uses
a division factor of 2^(pres + 1). The driver was missing the "+1",
causing the output period to be doubled.
This patch corrects the calculation to
2^(pres + 1), aligning itwith the hardware's behavior and ensuring the generated frequency is
correct.