diff options
Diffstat (limited to 'target/linux/bcm27xx/patches-4.19/950-0785-Pisound-MIDI-communication-fixes-for-scaled-down-CPU.patch')
| -rw-r--r-- | target/linux/bcm27xx/patches-4.19/950-0785-Pisound-MIDI-communication-fixes-for-scaled-down-CPU.patch | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/target/linux/bcm27xx/patches-4.19/950-0785-Pisound-MIDI-communication-fixes-for-scaled-down-CPU.patch b/target/linux/bcm27xx/patches-4.19/950-0785-Pisound-MIDI-communication-fixes-for-scaled-down-CPU.patch new file mode 100644 index 0000000000..c363e1d990 --- /dev/null +++ b/target/linux/bcm27xx/patches-4.19/950-0785-Pisound-MIDI-communication-fixes-for-scaled-down-CPU.patch @@ -0,0 +1,100 @@ +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) |