usb: cdnsp: Fix the IMAN_IE_SET and IMAN_IE_CLEAR macro.

Message ID d12bfcc9cbffb89e27b120668821b3c4f09b6755.1624390584.git.christophe.jaillet@wanadoo.fr
State New
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  • usb: cdnsp: Fix the IMAN_IE_SET and IMAN_IE_CLEAR macro.
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Commit Message

Christophe JAILLET June 22, 2021, 7:37 p.m.
IMAN_IE is BIT(1), so these macro are respectively equivalent to BIT(1)
and 0, whatever the value of 'p'.

The purpose was to set and reset a single bit in 'p'.
Fix these macros to do that correctly.

Fixes: e93e58d27402 ("usb: cdnsp: Device side header file for CDNSP driver")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
This patch is speculative. It is not tested.
Please, review with care.

Actually, the usage of these macros is:
   readl(somewhere)
   set or reset the IMAN_IE bit
   write(somewhere)
So it is likely that we want to preserve the other bits read. Otherwise,
the code could be much simpler.
---
 drivers/usb/cdns3/cdnsp-gadget.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Pawel Laszczak June 25, 2021, 4:23 a.m. | #1
>

>IMAN_IE is BIT(1), so these macro are respectively equivalent to BIT(1)

>and 0, whatever the value of 'p'.

>

>The purpose was to set and reset a single bit in 'p'.

>Fix these macros to do that correctly.

>

>Fixes: e93e58d27402 ("usb: cdnsp: Device side header file for CDNSP driver")

>Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>


Acked-by: Pawel Laszczak <pawell@cadence.com>


Currently the bit 1(RW) and bit 0 (W1toClr) are implemented. 
All other bits are not used and are reserved for future RW implementations.
I was a bit afraid about bit 0 which is "write 1 to clear" but I haven't found any
issue with this patch during testing so we can simplify these macros 

Thanks Christophe

>---

>This patch is speculative. It is not tested.

>Please, review with care.

>

>Actually, the usage of these macros is:

>   readl(somewhere)

>   set or reset the IMAN_IE bit

>   write(somewhere)

>So it is likely that we want to preserve the other bits read. Otherwise,

>the code could be much simpler.

>---

> drivers/usb/cdns3/cdnsp-gadget.h | 4 ++--

> 1 file changed, 2 insertions(+), 2 deletions(-)

>

>diff --git a/drivers/usb/cdns3/cdnsp-gadget.h b/drivers/usb/cdns3/cdnsp-gadget.h

>index 783ca8ffde00..f740fa6089d8 100644

>--- a/drivers/usb/cdns3/cdnsp-gadget.h

>+++ b/drivers/usb/cdns3/cdnsp-gadget.h

>@@ -383,8 +383,8 @@ struct cdnsp_intr_reg {

> #define IMAN_IE			BIT(1)

> #define IMAN_IP			BIT(0)

> /* bits 2:31 need to be preserved */

>-#define IMAN_IE_SET(p)		(((p) & IMAN_IE) | 0x2)

>-#define IMAN_IE_CLEAR(p)	(((p) & IMAN_IE) & ~(0x2))

>+#define IMAN_IE_SET(p)		((p) | IMAN_IE)

>+#define IMAN_IE_CLEAR(p)	((p) & ~IMAN_IE)

>

> /* IMOD - Interrupter Moderation Register - irq_control bitmasks. */

> /*

>--

>2.30.2


--

Regards,
Pawel Laszczak
Pawel Laszczak June 25, 2021, 4:39 a.m. | #2
Corrected Peter Chen address - should be peter.chen@kernel.org

>>IMAN_IE is BIT(1), so these macro are respectively equivalent to BIT(1)

>>and 0, whatever the value of 'p'.

>>

>>The purpose was to set and reset a single bit in 'p'.

>>Fix these macros to do that correctly.

>>

>>Fixes: e93e58d27402 ("usb: cdnsp: Device side header file for CDNSP driver")

>>Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>

>

>Acked-by: Pawel Laszczak <pawell@cadence.com>

>

>Currently the bit 1(RW) and bit 0 (W1toClr) are implemented.

>All other bits are not used and are reserved for future RW implementations.

>I was a bit afraid about bit 0 which is "write 1 to clear" but I haven't found any

>issue with this patch during testing so we can simplify these macros

>

>Thanks Christophe

>

>>---

>>This patch is speculative. It is not tested.

>>Please, review with care.

>>

>>Actually, the usage of these macros is:

>>   readl(somewhere)

>>   set or reset the IMAN_IE bit

>>   write(somewhere)

>>So it is likely that we want to preserve the other bits read. Otherwise,

>>the code could be much simpler.

>>---

>> drivers/usb/cdns3/cdnsp-gadget.h | 4 ++--

>> 1 file changed, 2 insertions(+), 2 deletions(-)

>>

>>diff --git a/drivers/usb/cdns3/cdnsp-gadget.h b/drivers/usb/cdns3/cdnsp-gadget.h

>>index 783ca8ffde00..f740fa6089d8 100644

>>--- a/drivers/usb/cdns3/cdnsp-gadget.h

>>+++ b/drivers/usb/cdns3/cdnsp-gadget.h

>>@@ -383,8 +383,8 @@ struct cdnsp_intr_reg {

>> #define IMAN_IE			BIT(1)

>> #define IMAN_IP			BIT(0)

>> /* bits 2:31 need to be preserved */

>>-#define IMAN_IE_SET(p)		(((p) & IMAN_IE) | 0x2)

>>-#define IMAN_IE_CLEAR(p)	(((p) & IMAN_IE) & ~(0x2))

>>+#define IMAN_IE_SET(p)		((p) | IMAN_IE)

>>+#define IMAN_IE_CLEAR(p)	((p) & ~IMAN_IE)

>>

>> /* IMOD - Interrupter Moderation Register - irq_control bitmasks. */

>> /*

>>--

>>2.30.2

>

>--

>

>Regards,

>Pawel Laszczak

Patch

diff --git a/drivers/usb/cdns3/cdnsp-gadget.h b/drivers/usb/cdns3/cdnsp-gadget.h
index 783ca8ffde00..f740fa6089d8 100644
--- a/drivers/usb/cdns3/cdnsp-gadget.h
+++ b/drivers/usb/cdns3/cdnsp-gadget.h
@@ -383,8 +383,8 @@  struct cdnsp_intr_reg {
 #define IMAN_IE			BIT(1)
 #define IMAN_IP			BIT(0)
 /* bits 2:31 need to be preserved */
-#define IMAN_IE_SET(p)		(((p) & IMAN_IE) | 0x2)
-#define IMAN_IE_CLEAR(p)	(((p) & IMAN_IE) & ~(0x2))
+#define IMAN_IE_SET(p)		((p) | IMAN_IE)
+#define IMAN_IE_CLEAR(p)	((p) & ~IMAN_IE)
 
 /* IMOD - Interrupter Moderation Register - irq_control bitmasks. */
 /*