[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PULL 05/12] hw/sd/bcm2835_sdhost: Don't raise spurious int
From: |
Peter Maydell |
Subject: |
[Qemu-devel] [PULL 05/12] hw/sd/bcm2835_sdhost: Don't raise spurious interrupts |
Date: |
Tue, 10 Apr 2018 13:17:17 +0100 |
The Linux bcm2835_sdhost driver doesn't work on QEMU, because our
model raises spurious data interrupts. Our function
bcm2835_sdhost_fifo_run() will flag an interrupt any time it is
called with s->datacnt == 0, even if the host hasn't actually issued
a data read or write command yet. This means that the driver gets a
spurious data interrupt as soon as it enables IRQs and then does
something else that causes us to call the fifo_run routine, like
writing to SDHCFG, and before it does the write to SDCMD to issue the
read. The driver's IRQ handler then spins forever complaining that
there's no data and the SD controller isn't in a state where there's
going to be any data:
[ 41.040738] sdhost-bcm2835 3f202000.mmc: fsm 1, hsts 00000000
[ 41.042059] sdhost-bcm2835 3f202000.mmc: fsm 1, hsts 00000000
(continues forever).
Move the interrupt flag setting to more plausible places:
* for BUSY, raise this as soon as a BUSYWAIT command has executed
* for DATA, raise this when the FIFO has any space free (for a write)
or any data in it (for a read)
* for BLOCK, raise this when the data count is 0 and we've
actually done some reading or writing
This is pure guesswork since the documentation for this hardware is
not public, but it is sufficient to get the Linux bcm2835_sdhost
driver to work.
Signed-off-by: Peter Maydell <address@hidden>
Reviewed-by: Philippe Mathieu-Daudé <address@hidden>
Tested-by: Gerd Hoffmann <address@hidden>
Message-id: address@hidden
---
hw/sd/bcm2835_sdhost.c | 46 ++++++++++++++++++++++++++--------------------
1 file changed, 26 insertions(+), 20 deletions(-)
diff --git a/hw/sd/bcm2835_sdhost.c b/hw/sd/bcm2835_sdhost.c
index 79f3c5ceeb..ebf3b926c2 100644
--- a/hw/sd/bcm2835_sdhost.c
+++ b/hw/sd/bcm2835_sdhost.c
@@ -137,6 +137,12 @@ static void bcm2835_sdhost_send_command(BCM2835SDHostState
*s)
}
#undef RWORD
}
+ /* We never really delay commands, so if this was a 'busywait' command
+ * then we've completed it now and can raise the interrupt.
+ */
+ if ((s->cmd & SDCMD_BUSYWAIT) && (s->config & SDHCFG_BUSY_IRPT_EN)) {
+ s->status |= SDHSTS_BUSY_IRPT;
+ }
return;
error:
@@ -187,18 +193,27 @@ static void bcm2835_sdhost_fifo_run(BCM2835SDHostState *s)
n++;
if (n == 4) {
bcm2835_sdhost_fifo_push(s, value);
+ s->status |= SDHSTS_DATA_FLAG;
+ if (s->config & SDHCFG_DATA_IRPT_EN) {
+ s->status |= SDHSTS_SDIO_IRPT;
+ }
n = 0;
value = 0;
}
}
if (n != 0) {
bcm2835_sdhost_fifo_push(s, value);
+ s->status |= SDHSTS_DATA_FLAG;
}
} else { /* write */
n = 0;
while (s->datacnt > 0 && (s->fifo_len > 0 || n > 0)) {
if (n == 0) {
value = bcm2835_sdhost_fifo_pop(s);
+ s->status |= SDHSTS_DATA_FLAG;
+ if (s->config & SDHCFG_DATA_IRPT_EN) {
+ s->status |= SDHSTS_SDIO_IRPT;
+ }
n = 4;
}
n--;
@@ -207,28 +222,19 @@ static void bcm2835_sdhost_fifo_run(BCM2835SDHostState *s)
value >>= 8;
}
}
+ if (s->datacnt == 0) {
+ s->edm &= ~SDEDM_FSM_MASK;
+ s->edm |= SDEDM_FSM_DATAMODE;
+ trace_bcm2835_sdhost_edm_change("datacnt 0", s->edm);
+
+ if ((s->cmd & SDCMD_WRITE_CMD) &&
+ (s->config & SDHCFG_BLOCK_IRPT_EN)) {
+ s->status |= SDHSTS_BLOCK_IRPT;
+ }
+ }
}
- if (s->datacnt == 0) {
- s->status |= SDHSTS_DATA_FLAG;
- s->edm &= ~0xf;
- s->edm |= SDEDM_FSM_DATAMODE;
- trace_bcm2835_sdhost_edm_change("datacnt 0", s->edm);
-
- if (s->config & SDHCFG_DATA_IRPT_EN) {
- s->status |= SDHSTS_SDIO_IRPT;
- }
-
- if ((s->cmd & SDCMD_BUSYWAIT) && (s->config & SDHCFG_BUSY_IRPT_EN)) {
- s->status |= SDHSTS_BUSY_IRPT;
- }
-
- if ((s->cmd & SDCMD_WRITE_CMD) && (s->config & SDHCFG_BLOCK_IRPT_EN)) {
- s->status |= SDHSTS_BLOCK_IRPT;
- }
-
- bcm2835_sdhost_update_irq(s);
- }
+ bcm2835_sdhost_update_irq(s);
s->edm &= ~(0x1f << 4);
s->edm |= ((s->fifo_len & 0x1f) << 4);
--
2.16.2
- [Qemu-devel] [PULL 00/12] target-arm queue, Peter Maydell, 2018/04/10
- [Qemu-devel] [PULL 10/12] linux-user/signal.c: Ensure AArch64 signal frame isn't too small, Peter Maydell, 2018/04/10
- [Qemu-devel] [PULL 12/12] fpu: Fix rounding mode for floatN_to_uintM_round_to_zero, Peter Maydell, 2018/04/10
- [Qemu-devel] [PULL 09/12] cpus.c: ensure running CPU recalculates icount deadlines on timer expiry, Peter Maydell, 2018/04/10
- [Qemu-devel] [PULL 11/12] tcg: Introduce tcg_set_insn_start_param, Peter Maydell, 2018/04/10
- [Qemu-devel] [PULL 01/12] hw/arm: Allow manually specified /psci node, Peter Maydell, 2018/04/10
- [Qemu-devel] [PULL 08/12] target/arm: Report unsupported MPU region sizes more clearly, Peter Maydell, 2018/04/10
- [Qemu-devel] [PULL 03/12] target-arm: Check undefined opcodes for SWP in A32 decoder, Peter Maydell, 2018/04/10
- [Qemu-devel] [PULL 05/12] hw/sd/bcm2835_sdhost: Don't raise spurious interrupts,
Peter Maydell <=
- [Qemu-devel] [PULL 04/12] hw/sd/bcm2835_sdhost: Add tracepoints, Peter Maydell, 2018/04/10
- [Qemu-devel] [PULL 07/12] hw/arm/fsl-imx: Fix introspection problem with fsl-imx6 and fsl-imx7, Peter Maydell, 2018/04/10
- [Qemu-devel] [PULL 02/12] hw/arm/integratorcp: Don't do things that could be fatal in the instance_init, Peter Maydell, 2018/04/10
- [Qemu-devel] [PULL 06/12] hw/arm/allwinner-a10: Do not use nd_table in instance_init function, Peter Maydell, 2018/04/10
- Re: [Qemu-devel] [PULL 00/12] target-arm queue, Peter Maydell, 2018/04/10