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| author | Vincent Fazio <vfazio@xes-inc.com> | 2021-09-14 13:19:18 -0500 |
|---|---|---|
| committer | Peter Robinson <pbrobinson@gmail.com> | 2023-03-24 14:43:20 +0000 |
| commit | 0a36afa82356b89ffc66ed7557d115186c5bd7f1 (patch) | |
| tree | 076a90713b5faf285461e6b17ba16a9491cc429b /arch/arm/mach-bcm283x | |
| parent | 0e8c94054fd80535e868900deb978a9a1ebcab67 (diff) | |
| download | u-boot-0a36afa82356b89ffc66ed7557d115186c5bd7f1.tar.gz u-boot-0a36afa82356b89ffc66ed7557d115186c5bd7f1.tar.bz2 u-boot-0a36afa82356b89ffc66ed7557d115186c5bd7f1.zip | |
arm: rpi: fallback to max clock rate for MMC clock
In rpi-firmware 25e2b597ebfb2495eab4816a276758dcc6ea21f1,
the GET_CLOCK_RATE mailbox property was changed to return the last
value set by SET_CLOCK_RATE.
https://github.com/raspberrypi/firmware/issues/1619#issuecomment-917025502
Due to this change in firmware behavior, bcm2835_get_mmc_clock now
returns a clock rate of zero since we do not issue SET_CLOCK_RATE.
This results in degraded MMC performance.
SET_CLOCK_RATE fixes the clock to a specific value and disables scaling
so is not an ideal solution.
Instead, fallback to GET_MAX_CLOCK_RATE in bcm2835_get_mmc_clock if
GET_CLOCK_RATE returns zero.
Signed-off-by: Vincent Fazio <vfazio@xes-inc.com>
Signed-off-by: Peter Robinson <pbrobinson@gmail.com>
Diffstat (limited to 'arch/arm/mach-bcm283x')
| -rw-r--r-- | arch/arm/mach-bcm283x/include/mach/mbox.h | 2 | ||||
| -rw-r--r-- | arch/arm/mach-bcm283x/msg.c | 19 |
2 files changed, 20 insertions, 1 deletions
diff --git a/arch/arm/mach-bcm283x/include/mach/mbox.h b/arch/arm/mach-bcm283x/include/mach/mbox.h index 2ae2d3d97c..7dcac583cc 100644 --- a/arch/arm/mach-bcm283x/include/mach/mbox.h +++ b/arch/arm/mach-bcm283x/include/mach/mbox.h @@ -224,6 +224,8 @@ struct bcm2835_mbox_tag_set_power_state { }; #define BCM2835_MBOX_TAG_GET_CLOCK_RATE 0x00030002 +#define BCM2835_MBOX_TAG_GET_MAX_CLOCK_RATE 0x00030004 +#define BCM2835_MBOX_TAG_GET_MIN_CLOCK_RATE 0x00030007 #define BCM2835_MBOX_CLOCK_ID_EMMC 1 #define BCM2835_MBOX_CLOCK_ID_UART 2 diff --git a/arch/arm/mach-bcm283x/msg.c b/arch/arm/mach-bcm283x/msg.c index fe243e2dca..68b2773875 100644 --- a/arch/arm/mach-bcm283x/msg.c +++ b/arch/arm/mach-bcm283x/msg.c @@ -75,6 +75,7 @@ int bcm2835_get_mmc_clock(u32 clock_id) { ALLOC_CACHE_ALIGN_BUFFER(struct msg_get_clock_rate, msg_clk, 1); int ret; + u32 clock_rate = 0; ret = bcm2835_power_on_module(BCM2835_MBOX_POWER_DEVID_SDHCI); if (ret) @@ -90,7 +91,23 @@ int bcm2835_get_mmc_clock(u32 clock_id) return -EIO; } - return msg_clk->get_clock_rate.body.resp.rate_hz; + clock_rate = msg_clk->get_clock_rate.body.resp.rate_hz; + + if (clock_rate == 0) { + BCM2835_MBOX_INIT_HDR(msg_clk); + BCM2835_MBOX_INIT_TAG(&msg_clk->get_clock_rate, GET_MAX_CLOCK_RATE); + msg_clk->get_clock_rate.body.req.clock_id = clock_id; + + ret = bcm2835_mbox_call_prop(BCM2835_MBOX_PROP_CHAN, &msg_clk->hdr); + if (ret) { + printf("bcm2835: Could not query max eMMC clock rate\n"); + return -EIO; + } + + clock_rate = msg_clk->get_clock_rate.body.resp.rate_hz; + } + + return clock_rate; } int bcm2835_get_video_size(int *widthp, int *heightp) |