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

From: Elliot Berman
Date: Tue Oct 11 2022 - 18:04:09 EST




On 10/10/2022 11:02 PM, Jiri Slaby wrote:
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.


Sure, I can do this instead.