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authorYoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>2016-08-29 18:00:38 +0900
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-09-24 10:07:39 +0200
commit59bc6b85d6a407aae0bb7135ea4da2aa00161f88 (patch)
treed97c68dd58e5cc20cd149fa0bd65a27c2b2616dd
parentb3e1877db1f25614b8db298abef4817c8a3d22c5 (diff)
usb: renesas_usbhs: fix clearing the {BRDY,BEMP}STS condition
commit 519d8bd4b5d3d82c413eac5bb42b106bb4b9ec15 upstream. The previous driver is possible to stop the transfer wrongly. For example: 1) An interrupt happens, but not BRDY interruption. 2) Read INTSTS0. And than state->intsts0 is not set to BRDY. 3) BRDY is set to 1 here. 4) Read BRDYSTS. 5) Clear the BRDYSTS. And then. the BRDY is cleared wrongly. Remarks: - The INTSTS0.BRDY is read only. - If any bits of BRDYSTS are set to 1, the BRDY is set to 1. - If BRDYSTS is 0, the BRDY is set to 0. So, this patch adds condition to avoid such situation. (And about NRDYSTS, this is not used for now. But, avoiding any side effects, this patch doesn't touch it.) Fixes: d5c6a1e024dd ("usb: renesas_usbhs: fixup interrupt status clear method") Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/usb/renesas_usbhs/mod.c11
1 files changed, 9 insertions, 2 deletions
diff --git a/drivers/usb/renesas_usbhs/mod.c b/drivers/usb/renesas_usbhs/mod.c
index d4be5d594896..28965ef4f824 100644
--- a/drivers/usb/renesas_usbhs/mod.c
+++ b/drivers/usb/renesas_usbhs/mod.c
@@ -282,9 +282,16 @@ static irqreturn_t usbhs_interrupt(int irq, void *data)
if (usbhs_mod_is_host(priv))
usbhs_write(priv, INTSTS1, ~irq_state.intsts1 & INTSTS1_MAGIC);
- usbhs_write(priv, BRDYSTS, ~irq_state.brdysts);
+ /*
+ * The driver should not clear the xxxSTS after the line of
+ * "call irq callback functions" because each "if" statement is
+ * possible to call the callback function for avoiding any side effects.
+ */
+ if (irq_state.intsts0 & BRDY)
+ usbhs_write(priv, BRDYSTS, ~irq_state.brdysts);
usbhs_write(priv, NRDYSTS, ~irq_state.nrdysts);
- usbhs_write(priv, BEMPSTS, ~irq_state.bempsts);
+ if (irq_state.intsts0 & BEMP)
+ usbhs_write(priv, BEMPSTS, ~irq_state.bempsts);
/*
* call irq callback functions