While trying to reproduce -EBUSY errors that our lab was getting in suspend/resume testing, I ended up finding a whole pile of problems with the Qualcomm GENI serial driver. I've posted a fix for the -EBUSY issue separately [1]. This series is fixing all of the Qualcomm GENI problems that I found. As far as I can tell most of the problems have been in the Qualcomm GENI serial driver since inception, but it can be noted that the behavior got worse with the new kfifo changes. Previously when the OS took data out of the circular queue we'd just spit stale data onto the serial port. Now we'll hard lockup. :-P I've tried to break this series up as much as possible to make it easier to understand but the final patch is still a lot of change at once. Hopefully it's OK. [1] https://lore.kernel.org/r/20240530084841.v2.1.I2395e66cf70c6e67d774c56943825c289b9c13e4@changeid Changes in v4: - Add GP_LENGTH field definition. - Fix indentation. - GENMASK(31, 0) -> GP_LENGTH. - Use uart_fifo_timeout_ms() for timeout. - tty: serial: Add uart_fifo_timeout_ms() Changes in v3: - 0xffffffff => GENMASK(31, 0) - Reword commit message. - Use uart_fifo_timeout() for timeout. Changes in v2: - Totally rework / rename patch to handle suspend while active xfer - serial: qcom-geni: Fix arg types for qcom_geni_serial_poll_bit() - serial: qcom-geni: Fix the timeout in qcom_geni_serial_poll_bit() - serial: qcom-geni: Introduce qcom_geni_serial_poll_bitfield() - serial: qcom-geni: Just set the watermark level once - serial: qcom-geni: Rework TX in FIFO mode to fix hangs/lockups - soc: qcom: geni-se: Add GP_LENGTH/IRQ_EN_SET/IRQ_EN_CLEAR registers Douglas Anderson (8): soc: qcom: geni-se: Add GP_LENGTH/IRQ_EN_SET/IRQ_EN_CLEAR registers tty: serial: Add uart_fifo_timeout_ms() serial: qcom-geni: Fix the timeout in qcom_geni_serial_poll_bit() serial: qcom-geni: Fix arg types for qcom_geni_serial_poll_bit() serial: qcom-geni: Introduce qcom_geni_serial_poll_bitfield() serial: qcom-geni: Just set the watermark level once serial: qcom-geni: Fix suspend while active UART xfer serial: qcom-geni: Rework TX in FIFO mode to fix hangs/lockups drivers/tty/serial/qcom_geni_serial.c | 322 +++++++++++++++----------- include/linux/serial_core.h | 15 +- include/linux/soc/qcom/geni-se.h | 9 + 3 files changed, 206 insertions(+), 140 deletions(-) -- 2.45.2.505.gda0bf45e8d-goog
