Re: [PATCH v8 2/3] CMDQ: Mediatek CMDQ driver

Matthias Brugger
2016-06-07T17:04:27Z

On 30/05/16 05:19, HS Liao wrote:
> This patch is first version of Mediatek Command Queue(CMDQ) driver. The
> CMDQ is used to help read/write registers with critical time limitation,
> such as updating display configuration during the vblank. It controls
> Global Command Engine (GCE) hardware to achieve this requirement.
> Currently, CMDQ only supports display related hardwares, but we expect
> it can be extended to other hardwares for future requirements.
>
> Signed-off-by: HS Liao <hs.liao@mediatek.com>
> Signed-off-by: CK Hu <ck.hu@mediatek.com>
> ---

[...]

> +static void cmdq_handle_error_done(struct cmdq *cmdq,
> + struct cmdq_thread *thread, u32 irq_flag)
> +{
> + struct cmdq_task *task, *tmp, *curr_task = NULL;
> + u32 curr_pa;
> + struct cmdq_cb_data cmdq_cb_data;
> + bool err;
> +
> + if (irq_flag & CMDQ_THR_IRQ_ERROR)
> + err = true;
> + else if (irq_flag & CMDQ_THR_IRQ_DONE)
> + err = false;
> + else
> + return;
> +
> + curr_pa = cmdq_thread_readl(thread, CMDQ_THR_CURR_ADDR);
> +
> + list_for_each_entry_safe(task, tmp, &thread->task_busy_list,
> + list_entry) {
> + if (curr_pa >= task->pa_base &&
> + curr_pa < (task->pa_base + task->command_size))
> + curr_task = task;
> + if (task->cb.cb) {
> + cmdq_cb_data.err = curr_task ? err : false;
> + cmdq_cb_data.data = task->cb.data;
> + task->cb.cb(cmdq_cb_data);
> + }

I think this is not right. If we got an IRQ_DONE, then the current task
is in execution, we should not call the callback until it has finished.

Regards,
Matthias