net: ethernet: ti: am65-cpsw: Add RX DMA Channel Teardown Quirk
authorSiddharth Vadapalli <s-vadapalli@ti.com>
Thu, 9 Feb 2023 08:44:32 +0000 (14:14 +0530)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 22 Feb 2023 11:59:51 +0000 (12:59 +0100)
commitb7ec3971f1832528e8612067a2a197bc15d884b3
tree94aae76d1ad4bef21668eb223e75c6dde889fdd9
parentec9938d1b56e39a2e1d1381fe296c3ec647b4f5e
net: ethernet: ti: am65-cpsw: Add RX DMA Channel Teardown Quirk

commit 0ed577e7e8e508c24e22ba07713ecc4903e147c3 upstream.

In TI's AM62x/AM64x SoCs, successful teardown of RX DMA Channel raises an
interrupt. The process of servicing this interrupt involves flushing all
pending RX DMA descriptors and clearing the teardown completion marker
(TDCM). The am65_cpsw_nuss_rx_packets() function invoked from the RX
NAPI callback services the interrupt. Thus, it is necessary to wait for
this handler to run, drain all packets and clear TDCM, before calling
napi_disable() in am65_cpsw_nuss_common_stop() function post channel
teardown. If napi_disable() executes before ensuring that TDCM is
cleared, the TDCM remains set when the interfaces are down, resulting in
an interrupt storm when the interfaces are brought up again.

Since the interrupt raised to indicate the RX DMA Channel teardown is
specific to the AM62x and AM64x SoCs, add a quirk for it.

Fixes: 4f7cce272403 ("net: ethernet: ti: am65-cpsw: add support for am64x cpsw3g")
Co-developed-by: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>
Reviewed-by: Roger Quadros <rogerq@kernel.org>
Link: https://lore.kernel.org/r/20230209084432.189222-1-s-vadapalli@ti.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/net/ethernet/ti/am65-cpsw-nuss.c
drivers/net/ethernet/ti/am65-cpsw-nuss.h