|
 |
b73fa7b |
From 71ba043e5c5575f3d86536acade70dab6599489b Mon Sep 17 00:00:00 2001
|
|
|
b73fa7b |
From: Vincent Fazio <vfazio@xes-inc.com>
|
|
|
b73fa7b |
Date: Mon, 13 Sep 2021 11:22:30 -0500
|
|
|
b73fa7b |
Subject: [PATCH] arm: rpi: fallback to max clock rate for MMC clock
|
|
|
b73fa7b |
|
|
|
b73fa7b |
In rpi-firmware 25e2b597ebfb2495eab4816a276758dcc6ea21f1 and later,
|
|
|
b73fa7b |
the GET_CLOCK_RATE mailbox property was changed to return the last
|
|
|
b73fa7b |
value set by SET_CLOCK_RATE.
|
|
|
b73fa7b |
|
|
|
b73fa7b |
https://github.com/raspberrypi/firmware/issues/1619#issuecomment-917025502
|
|
|
b73fa7b |
|
|
|
b73fa7b |
U-Boot does not call SET_CLOCK_RATE so bcm2835_get_mmc_clock will
|
|
|
b73fa7b |
return zero and can cause degraded MMC performance.
|
|
|
b73fa7b |
|
|
|
b73fa7b |
Calling SET_CLOCK_RATE fixes the frequency of the clock to a specific
|
|
|
b73fa7b |
value and disables the firmware's clock scaling so is not an option.
|
|
|
b73fa7b |
|
|
|
b73fa7b |
Instead, fallback to GET_MAX_CLOCK_RATE in bcm2835_get_mmc_clock if
|
|
|
b73fa7b |
GET_CLOCK_RATE returns zero.
|
|
|
b73fa7b |
|
|
|
b73fa7b |
Signed-off-by: Vincent Fazio <vfazio@xes-inc.com>
|
|
|
b73fa7b |
---
|
|
|
b73fa7b |
arch/arm/mach-bcm283x/include/mach/mbox.h | 2 ++
|
|
|
b73fa7b |
arch/arm/mach-bcm283x/msg.c | 20 +++++++++++++++++++-
|
|
|
b73fa7b |
2 files changed, 21 insertions(+), 1 deletion(-)
|
|
|
b73fa7b |
|
|
|
b73fa7b |
diff --git a/arch/arm/mach-bcm283x/include/mach/mbox.h b/arch/arm/mach-bcm283x/include/mach/mbox.h
|
|
|
b73fa7b |
index 2ae2d3d97c3..7dcac583cc4 100644
|
|
|
b73fa7b |
--- a/arch/arm/mach-bcm283x/include/mach/mbox.h
|
|
|
b73fa7b |
+++ b/arch/arm/mach-bcm283x/include/mach/mbox.h
|
|
|
b73fa7b |
@@ -224,6 +224,8 @@ struct bcm2835_mbox_tag_set_power_state {
|
|
|
b73fa7b |
};
|
|
|
b73fa7b |
|
|
|
b73fa7b |
#define BCM2835_MBOX_TAG_GET_CLOCK_RATE 0x00030002
|
|
|
b73fa7b |
+#define BCM2835_MBOX_TAG_GET_MAX_CLOCK_RATE 0x00030004
|
|
|
b73fa7b |
+#define BCM2835_MBOX_TAG_GET_MIN_CLOCK_RATE 0x00030007
|
|
|
b73fa7b |
|
|
|
b73fa7b |
#define BCM2835_MBOX_CLOCK_ID_EMMC 1
|
|
|
b73fa7b |
#define BCM2835_MBOX_CLOCK_ID_UART 2
|
|
|
b73fa7b |
diff --git a/arch/arm/mach-bcm283x/msg.c b/arch/arm/mach-bcm283x/msg.c
|
|
|
b73fa7b |
index 347aece3cd8..e2badfecb09 100644
|
|
|
b73fa7b |
--- a/arch/arm/mach-bcm283x/msg.c
|
|
|
b73fa7b |
+++ b/arch/arm/mach-bcm283x/msg.c
|
|
|
b73fa7b |
@@ -75,6 +75,7 @@ int bcm2835_get_mmc_clock(u32 clock_id)
|
|
|
b73fa7b |
{
|
|
|
b73fa7b |
ALLOC_CACHE_ALIGN_BUFFER(struct msg_get_clock_rate, msg_clk, 1);
|
|
|
b73fa7b |
int ret;
|
|
|
b73fa7b |
+ u32 clock_rate = 0;
|
|
|
b73fa7b |
|
|
|
b73fa7b |
ret = bcm2835_power_on_module(BCM2835_MBOX_POWER_DEVID_SDHCI);
|
|
|
b73fa7b |
if (ret)
|
|
|
b73fa7b |
@@ -90,7 +91,24 @@ int bcm2835_get_mmc_clock(u32 clock_id)
|
|
|
b73fa7b |
return -EIO;
|
|
|
b73fa7b |
}
|
|
|
b73fa7b |
|
|
|
b73fa7b |
- return msg_clk->get_clock_rate.body.resp.rate_hz;
|
|
|
b73fa7b |
+ clock_rate = msg_clk->get_clock_rate.body.resp.rate_hz;
|
|
|
b73fa7b |
+
|
|
|
b73fa7b |
+ if (clock_rate == 0)
|
|
|
b73fa7b |
+ {
|
|
|
b73fa7b |
+ BCM2835_MBOX_INIT_HDR(msg_clk);
|
|
|
b73fa7b |
+ BCM2835_MBOX_INIT_TAG(&msg_clk->get_clock_rate, GET_MAX_CLOCK_RATE);
|
|
|
b73fa7b |
+ msg_clk->get_clock_rate.body.req.clock_id = clock_id;
|
|
|
b73fa7b |
+
|
|
|
b73fa7b |
+ ret = bcm2835_mbox_call_prop(BCM2835_MBOX_PROP_CHAN, &msg_clk->hdr);
|
|
|
b73fa7b |
+ if (ret) {
|
|
|
b73fa7b |
+ printf("bcm2835: Could not query max eMMC clock rate\n");
|
|
|
b73fa7b |
+ return -EIO;
|
|
|
b73fa7b |
+ }
|
|
|
b73fa7b |
+
|
|
|
b73fa7b |
+ clock_rate = msg_clk->get_clock_rate.body.resp.rate_hz;
|
|
|
b73fa7b |
+ }
|
|
|
b73fa7b |
+
|
|
|
b73fa7b |
+ return clock_rate;
|
|
|
b73fa7b |
}
|
|
|
b73fa7b |
|
|
|
b73fa7b |
int bcm2835_get_video_size(int *widthp, int *heightp)
|