openwrt/target/linux/bcm27xx/patches-4.19/950-0785-Pisound-MIDI-communication-fixes-for-scaled-down-CPU.patch
Adrian Schmutzler 7d7aa2fd92 brcm2708: rename target to bcm27xx
This change makes the names of Broadcom targets consistent by using
the common notation based on SoC/CPU ID (which is used internally
anyway), bcmXXXX instead of brcmXXXX.
This is even used for target TITLE in make menuconfig already,
only the short target name used brcm so far.

Despite, since subtargets range from bcm2708 to bcm2711, it seems
appropriate to use bcm27xx instead of bcm2708 (again, as already done
for BOARDNAME).

This also renames the packages brcm2708-userland and brcm2708-gpu-fw.

Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
Acked-by: Álvaro Fernández Rojas <noltari@gmail.com>
2020-02-14 14:10:51 +01:00

101 lines
3.2 KiB
Diff

From 5b12b655f266ea29e91a7b7a46385df05bb70ed8 Mon Sep 17 00:00:00 2001
From: Giedrius <giedrius@blokas.io>
Date: Tue, 7 Jan 2020 11:04:21 +0200
Subject: [PATCH] Pisound: MIDI communication fixes for scaled down
CPU.
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
* Increased maximum SPI communication speed to avoid running too slow
when the CPU is scaled down and losing MIDI data.
* Keep track of buffer usage in millibytes for higher precision.
Signed-off-by: Giedrius Trainavičius <giedrius@blokas.io>
---
sound/soc/bcm/pisound.c | 31 ++++++++++++++++++-------------
1 file changed, 18 insertions(+), 13 deletions(-)
--- a/sound/soc/bcm/pisound.c
+++ b/sound/soc/bcm/pisound.c
@@ -1,6 +1,6 @@
/*
* Pisound Linux kernel module.
- * Copyright (C) 2016-2019 Vilniaus Blokas UAB, https://blokas.io/pisound
+ * Copyright (C) 2016-2020 Vilniaus Blokas UAB, https://blokas.io/pisound
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
@@ -326,7 +326,7 @@ static void spi_transfer(const uint8_t *
transfer.tx_buf = txbuf;
transfer.rx_buf = rxbuf;
transfer.len = len;
- transfer.speed_hz = 100000;
+ transfer.speed_hz = 150000;
transfer.delay_usecs = 10;
spi_message_add_tail(&transfer, &msg);
@@ -403,9 +403,9 @@ static struct spi_device *pisnd_spi_find
static void pisnd_work_handler(struct work_struct *work)
{
enum { TRANSFER_SIZE = 4 };
- enum { PISOUND_OUTPUT_BUFFER_SIZE = 128 };
- enum { MIDI_BYTES_PER_SECOND = 3125 };
- int out_buffer_used = 0;
+ enum { PISOUND_OUTPUT_BUFFER_SIZE_MILLIBYTES = 127 * 1000 };
+ enum { MIDI_MILLIBYTES_PER_JIFFIE = (3125 * 1000) / HZ };
+ int out_buffer_used_millibytes = 0;
unsigned long now;
uint8_t val;
uint8_t txbuf[TRANSFER_SIZE];
@@ -445,7 +445,9 @@ static void pisnd_work_handler(struct wo
had_data = false;
memset(txbuf, 0, sizeof(txbuf));
for (i = 0; i < sizeof(txbuf) &&
- out_buffer_used < PISOUND_OUTPUT_BUFFER_SIZE;
+ ((out_buffer_used_millibytes+1000 <
+ PISOUND_OUTPUT_BUFFER_SIZE_MILLIBYTES) ||
+ g_ledFlashDurationChanged);
i += 2) {
val = 0;
@@ -458,7 +460,7 @@ static void pisnd_work_handler(struct wo
} else if (kfifo_get(&spi_fifo_out, &val)) {
txbuf[i+0] = 0x0f;
txbuf[i+1] = val;
- ++out_buffer_used;
+ out_buffer_used_millibytes += 1000;
}
}
@@ -469,12 +471,14 @@ static void pisnd_work_handler(struct wo
* rate.
*/
now = jiffies;
- out_buffer_used -=
- (MIDI_BYTES_PER_SECOND / HZ) /
- (now - last_transfer_at);
- if (out_buffer_used < 0)
- out_buffer_used = 0;
- last_transfer_at = now;
+ if (now != last_transfer_at) {
+ out_buffer_used_millibytes -=
+ (now - last_transfer_at) *
+ MIDI_MILLIBYTES_PER_JIFFIE;
+ if (out_buffer_used_millibytes < 0)
+ out_buffer_used_millibytes = 0;
+ last_transfer_at = now;
+ }
for (i = 0; i < sizeof(rxbuf); i += 2) {
if (rxbuf[i]) {
@@ -489,6 +493,7 @@ static void pisnd_work_handler(struct wo
|| !kfifo_is_empty(&spi_fifo_out)
|| pisnd_spi_has_more()
|| g_ledFlashDurationChanged
+ || out_buffer_used_millibytes != 0
);
if (!kfifo_is_empty(&spi_fifo_in) && g_recvCallback)