Commit "mmc: mmci: Handle CMD irq before DATA irq", caused an issue
when using the ARM model of the PL181 and running QEMU.
The bug was reported for the following QEMU version:
$ qemu-system-arm -version
QEMU emulator version 2.0.0 (Debian 2.0.0+dfsg-2ubuntu1.1), Copyright
(c) 2003-2008 Fabrice Bellard
To resolve the problem, let's restore the old behavior were the DATA
irq is handled prior the CMD irq, but only for the arm_variant, which
the problem was reported for.
Reported-by: John Stultz <john.stultz@xxxxxxxxxx>
Cc: Peter Maydell <peter.maydell@xxxxxxxxxx>
Cc: Russell King <linux@xxxxxxxxxxxxxxxx>
Tested-by: Kees Cook <keescook@xxxxxxxxxxxx>
Tested-by: John Stultz <john.stultz@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # v3.15+
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
[kees: backported to 3.16]
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
This is the back-port to 3.16, in response to "FAILED: patch "[PATCH]
mmc: mmci: Reverse IRQ handling for the arm_variant" failed to apply to
3.16-stable tree"
---
drivers/mmc/host/mmci.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 249ab80cbb45..d3f05ad33f09 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -65,6 +65,7 @@ static unsigned int fmax = 515633;
* @pwrreg_clkgate: MMCIPOWER register must be used to gate the clock
* @busy_detect: true if busy detection on dat0 is supported
* @pwrreg_nopower: bits in MMCIPOWER don't controls ext. power supply
+ * @reversed_irq_handling: handle data irq before cmd irq.
*/
struct variant_data {
unsigned int clkreg;
@@ -80,6 +81,7 @@ struct variant_data {
bool pwrreg_clkgate;
bool busy_detect;
bool pwrreg_nopower;
+ bool reversed_irq_handling;
};
static struct variant_data variant_arm = {
@@ -87,6 +89,7 @@ static struct variant_data variant_arm = {
.fifohalfsize = 8 * 4,
.datalength_bits = 16,
.pwrreg_powerup = MCI_PWR_UP,
+ .reversed_irq_handling = true,
};
static struct variant_data variant_arm_extended_fifo = {
@@ -1163,8 +1166,13 @@ static irqreturn_t mmci_irq(int irq, void *dev_id)
dev_dbg(mmc_dev(host->mmc), "irq0 (data+cmd) %08x\n", status);
- mmci_cmd_irq(host, host->cmd, status);
- mmci_data_irq(host, host->data, status);
+ if (host->variant->reversed_irq_handling) {
+ mmci_data_irq(host, host->data, status);
+ mmci_cmd_irq(host, host->cmd, status);
+ } else {
+ mmci_cmd_irq(host, host->cmd, status);
+ mmci_data_irq(host, host->data, status);
+ }
/* Don't poll for busy completion in irq context. */
if (host->busy_status)
--
1.9.1
--
Kees Cook
Chrome OS Security
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