Re: [PATCH v5 13/13] tty: gunyah: Add tty console driver for RM Console Services

[Jiri Slaby]

On 11. 10. 22, 2:08, Elliot Berman wrote:
> Gunyah provides a console for each VM using the VM console resource
> manager APIs. This driver allows console data from other
> VMs to be accessed via a TTY device and exports a console device to dump
> Linux's own logs to our console.
...
> +struct rm_cons_drv_data {
> +	struct tty_driver *tty_driver;
> +	struct device *dev;
> +
> +	spinlock_t ports_lock;
> +	struct rm_cons_port *ports[RM_CONS_TTY_ADAPATERS];
> +
> +	struct notifier_block rm_cons_notif;
> +	struct console console;
> +
> +	/* below are for printk console.
> +	 * gh_rm_console_* calls will sleep and console_write can be called from
> +	 * atomic ctx. Two xmit buffers are used. The active buffer is tracked with
> +	 * co_xmit_idx. Writes go into the co_xmit_buf[co_xmit_idx] buffer.
> +	 * A work is scheduled to flush the bytes. The work will swap the active buffer
> +	 * and write out the other buffer.
> +	 */

Ugh, why? This is too ugly and unnecessary. What about passing the kfifo 
to gh_rm_console_write() instead? You do memcpy() there anyway.

> +	char *co_xmit_buf[2];
> +	int co_xmit_idx;
> +	unsigned int co_xmit_count;
> +	spinlock_t co_xmit_lock;
> +	struct work_struct co_flush_work;
> +};
> +
> +static int rm_cons_notif_handler(struct notifier_block *nb, unsigned long cmd, void *data)
> +{
> +	int count, i;
> +	struct rm_cons_port *rm_port = NULL;
> +	struct tty_port *tty_port = NULL;
> +	struct rm_cons_drv_data *cons_data =
> +		container_of(nb, struct rm_cons_drv_data, rm_cons_notif);
> +	const struct gh_rm_notification *notif = data;
> +	struct gh_rm_notif_vm_console_chars const * const msg = notif->buff;

So you did not comment on/address all my notes?

--
js