mirror of
https://github.com/openwrt/openwrt.git
synced 2024-12-22 06:57:57 +00:00
51 lines
1.8 KiB
Diff
51 lines
1.8 KiB
Diff
From 5010dba0e3f6f2c9d623e265276d9b6993fa96b0 Mon Sep 17 00:00:00 2001
|
|
From: Phil Elwell <phil@raspberrypi.org>
|
|
Date: Fri, 26 Oct 2018 17:29:51 +0100
|
|
Subject: [PATCH] mmc/bcm2835-sdhost: Recover from MMC_SEND_EXT_CSD
|
|
|
|
If the user issues an "mmc extcsd read", the SD controller receives
|
|
what it thinks is a SEND_IF_COND command with an unexpected data block.
|
|
The resulting operations leave the FSM stuck in READWAIT, a state which
|
|
persists until the MMC framework resets the controller, by which point
|
|
the root filesystem is likely to have been unmounted.
|
|
|
|
A less heavyweight solution is to detect the condition and nudge the
|
|
FSM by asserting the (self-clearing) FORCE_DATA_MODE bit.
|
|
|
|
N.B. This workaround was essentially discovered by accident and without
|
|
a full understanding the inner workings of the controller, so it is
|
|
fortunate that the "fix" only modifies error paths.
|
|
|
|
See: https://github.com/raspberrypi/linux/issues/2728
|
|
|
|
Signed-off-by: Phil Elwell <phil@raspberrypi.org>
|
|
---
|
|
drivers/mmc/host/bcm2835-sdhost.c | 9 +++++++++
|
|
1 file changed, 9 insertions(+)
|
|
|
|
--- a/drivers/mmc/host/bcm2835-sdhost.c
|
|
+++ b/drivers/mmc/host/bcm2835-sdhost.c
|
|
@@ -1244,6 +1244,8 @@ static void bcm2835_sdhost_finish_comman
|
|
pr_info("%s: ignoring CRC7 error for CMD1\n",
|
|
mmc_hostname(host->mmc));
|
|
} else {
|
|
+ u32 edm, fsm;
|
|
+
|
|
if (sdhsts & SDHSTS_CMD_TIME_OUT) {
|
|
if (host->debug)
|
|
pr_warn("%s: command %d timeout\n",
|
|
@@ -1256,6 +1258,13 @@ static void bcm2835_sdhost_finish_comman
|
|
host->cmd->opcode);
|
|
host->cmd->error = -EILSEQ;
|
|
}
|
|
+
|
|
+ edm = readl(host->ioaddr + SDEDM);
|
|
+ fsm = edm & SDEDM_FSM_MASK;
|
|
+ if (fsm == SDEDM_FSM_READWAIT ||
|
|
+ fsm == SDEDM_FSM_WRITESTART1)
|
|
+ writel(edm | SDEDM_FORCE_DATA_MODE,
|
|
+ host->ioaddr + SDEDM);
|
|
tasklet_schedule(&host->finish_tasklet);
|
|
return;
|
|
}
|