Patch "dmaengine: apple-admac: Handle 'global' interrupt flags" has been added to the 6.1-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    dmaengine: apple-admac: Handle 'global' interrupt flags

to the 6.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     dmaengine-apple-admac-handle-global-interrupt-flags.patch
and it can be found in the queue-6.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 4a48a731efe345a1cb470dc0e0a70b45dae5c314
Author: Martin Povišer <povik+lin@xxxxxxxxxxx>
Date:   Fri Feb 24 16:22:20 2023 +0100

    dmaengine: apple-admac: Handle 'global' interrupt flags
    
    [ Upstream commit a288fd158fbf85c06a9ac01cecabf97ac5d962e7 ]
    
    In addition to TX channel and RX channel interrupt flags there's
    another class of 'global' interrupt flags with unknown semantics. Those
    weren't being handled up to now, and they are the suspected cause of
    stuck IRQ states that have been sporadically occurring. Check the global
    flags and clear them if raised.
    
    Fixes: b127315d9a78 ("dmaengine: apple-admac: Add Apple ADMAC driver")
    Signed-off-by: Martin Povišer <povik+lin@xxxxxxxxxxx>
    Link: https://lore.kernel.org/r/20230224152222.26732-1-povik+lin@xxxxxxxxxxx
    Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/dma/apple-admac.c b/drivers/dma/apple-admac.c
index 90f28bda29c8b..00cbfafe0ed9d 100644
--- a/drivers/dma/apple-admac.c
+++ b/drivers/dma/apple-admac.c
@@ -75,6 +75,7 @@
 
 #define REG_TX_INTSTATE(idx)		(0x0030 + (idx) * 4)
 #define REG_RX_INTSTATE(idx)		(0x0040 + (idx) * 4)
+#define REG_GLOBAL_INTSTATE(idx)	(0x0050 + (idx) * 4)
 #define REG_CHAN_INTSTATUS(ch, idx)	(0x8010 + (ch) * 0x200 + (idx) * 4)
 #define REG_CHAN_INTMASK(ch, idx)	(0x8020 + (ch) * 0x200 + (idx) * 4)
 
@@ -672,13 +673,14 @@ static void admac_handle_chan_int(struct admac_data *ad, int no)
 static irqreturn_t admac_interrupt(int irq, void *devid)
 {
 	struct admac_data *ad = devid;
-	u32 rx_intstate, tx_intstate;
+	u32 rx_intstate, tx_intstate, global_intstate;
 	int i;
 
 	rx_intstate = readl_relaxed(ad->base + REG_RX_INTSTATE(ad->irq_index));
 	tx_intstate = readl_relaxed(ad->base + REG_TX_INTSTATE(ad->irq_index));
+	global_intstate = readl_relaxed(ad->base + REG_GLOBAL_INTSTATE(ad->irq_index));
 
-	if (!tx_intstate && !rx_intstate)
+	if (!tx_intstate && !rx_intstate && !global_intstate)
 		return IRQ_NONE;
 
 	for (i = 0; i < ad->nchannels; i += 2) {
@@ -693,6 +695,12 @@ static irqreturn_t admac_interrupt(int irq, void *devid)
 		rx_intstate >>= 1;
 	}
 
+	if (global_intstate) {
+		dev_warn(ad->dev, "clearing unknown global interrupt flag: %x\n",
+			 global_intstate);
+		writel_relaxed(~(u32) 0, ad->base + REG_GLOBAL_INTSTATE(ad->irq_index));
+	}
+
 	return IRQ_HANDLED;
 }