| Message ID | 20230307155543.31021-2-srinivas.kandagatla@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | [1/2] tty: serial: qcom-geni-serial: check correct dma address before unprep | expand |
diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c index 5972b5c317d3..bb63a00f4c07 100644 --- a/drivers/tty/serial/qcom_geni_serial.c +++ b/drivers/tty/serial/qcom_geni_serial.c @@ -637,6 +637,9 @@ static void qcom_geni_serial_start_tx_dma(struct uart_port *uport) xmit_size = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE); + if (!xmit_size) + return; + qcom_geni_serial_setup_tx(uport, xmit_size); ret = geni_se_tx_dma_prep(&port->se, &xmit->buf[xmit->tail],
Check if there are valid length of bytes to transfer before starting dma. without this check we can see below kernel warning when we try to map a zero size buffers. ------------[ cut here ]------------ WARNING: CPU: 0 PID: 0 at drivers/iommu/dma-iommu.c:1046 iommu_dma_unmap_page+0xe0/0xfc Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 6.3.0-rc1-dirty #347 Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT) pstate: 804000c5 (Nzcv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : iommu_dma_unmap_page+0xe0/0xfc lr : iommu_dma_unmap_page+0x38/0xfc ... Call trace: iommu_dma_unmap_page+0xe0/0xfc dma_unmap_page_attrs+0x30/0x1ec geni_se_tx_dma_unprep+0x58/0x80 qcom_geni_serial_isr+0x350/0x750 __handle_irq_event_percpu+0x58/0x148 handle_irq_event_percpu+0x18/0x4c handle_irq_event+0x48/0x88 handle_fasteoi_irq+0xb0/0x130 generic_handle_domain_irq+0x2c/0x44 gic_handle_irq+0xd4/0x140 call_on_irq_stack+0x24/0x4c do_interrupt_handler+0x80/0x84 el1_interrupt+0x38/0x6c el1h_64_irq_handler+0x18/0x24 el1h_64_irq+0x64/0x68 cpuidle_enter_state+0x1e4/0x310 cpuidle_enter+0x3c/0x54 call_cpuidle+0x1c/0x40 do_idle+0x204/0x260 cpu_startup_entry+0x28/0x2c kernel_init+0x0/0x12c arch_post_acpi_subsys_init+0x0/0x8 start_kernel+0x3cc/0x74c __primary_switched+0xbc/0xc4 Fixes: 2aaa43c70778 ("tty: serial: qcom-geni-serial: add support for serial engine DMA") Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> --- drivers/tty/serial/qcom_geni_serial.c | 3 +++ 1 file changed, 3 insertions(+)