[PATCH] usb: musb: Fix fifo reads for dm816x with musb_dsps

[PATCH] usb: musb: Fix fifo reads for dm816x with musb_dsps

[Tony Lindgren]

Looks like dm81xx can only do 32-bit fifo reads like am35x. Let's set
up musb-dsps with a custom read_fifo function based on the compatible
flag.

Otherwise we can get the following errors when starting dhclient on a
asix USB Ethernet adapter:

asix 2-1:1.0 eth2: asix_rx_fixup() Bad Header Length 0xffff003c, offset 4

While at it, let's also remove pointless cast of the driver data.

Cc: Bin Liu <binmlist@gmail.com>
Cc: Brian Hutchinson <b.hutchman@gmail.com>
Cc: George Cherian <george.cherian@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
---
 drivers/usb/musb/musb_dsps.c | 37 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 36 insertions(+), 1 deletion(-)

--- a/drivers/usb/musb/musb_dsps.c
+++ b/drivers/usb/musb/musb_dsps.c
@@ -655,6 +655,36 @@ static int dsps_musb_reset(struct musb *musb)
 	return !session_restart;
 }
 
+/* Similar to am35x, dm81xx support only 32-bit read operation */
+static void dsps_read_fifo32(struct musb_hw_ep *hw_ep, u16 len, u8 *dst)
+{
+	void __iomem *fifo = hw_ep->fifo;
+	u32		val;
+	int		i;
+
+	/* Read for 32bit-aligned destination address */
+	if (likely((0x03 & (unsigned long)dst) == 0) && len >= 4) {
+		readsl(fifo, dst, len >> 2);
+		dst += len & ~0x03;
+		len &= 0x03;
+	}
+	/*
+	 * Now read the remaining 1 to 3 byte or complete length if
+	 * unaligned address.
+	 */
+	if (len > 4) {
+		for (i = 0; i < (len >> 2); i++) {
+			*(u32 *)dst = musb_readl(fifo, 0);
+			dst += 4;
+		}
+		len &= 0x03;
+	}
+	if (len > 0) {
+		val = musb_readl(fifo, 0);
+		memcpy(dst, &val, len);
+	}
+}
+
 static struct musb_platform_ops dsps_ops = {
 	.quirks		= MUSB_INDEXED_EP,
 	.init		= dsps_musb_init,
@@ -802,6 +832,9 @@ static int dsps_probe(struct platform_device *pdev)
 	}
 	wrp = match->data;
 
+	if (of_device_is_compatible(pdev->dev.of_node, "ti,musb-dm816"))
+		dsps_ops.read_fifo = dsps_read_fifo32;
+
 	/* allocate glue */
 	glue = devm_kzalloc(&pdev->dev, sizeof(*glue), GFP_KERNEL);
 	if (!glue)
@@ -878,7 +911,9 @@ static const struct dsps_musb_wrapper am33xx_driver_data = {
 
 static const struct of_device_id musb_dsps_of_match[] = {
 	{ .compatible = "ti,musb-am33xx",
-		.data = (void *) &am33xx_driver_data, },
+		.data = &am33xx_driver_data, },
+	{ .compatible = "ti,musb-dm816",
+		.data = &am33xx_driver_data, },
 	{  },
 };
 MODULE_DEVICE_TABLE(of, musb_dsps_of_match);
-- 
2.1.4

Re: [PATCH] usb: musb: Fix fifo reads for dm816x with musb_dsps

[Sergei Shtylyov]

Hello.

On 3/19/2015 1:48 AM, Tony Lindgren wrote:

> Looks like dm81xx can only do 32-bit fifo reads like am35x. Let's set
> up musb-dsps with a custom read_fifo function based on the compatible
> flag.

> Otherwise we can get the following errors when starting dhclient on a
> asix USB Ethernet adapter:

> asix 2-1:1.0 eth2: asix_rx_fixup() Bad Header Length 0xffff003c, offset 4

> While at it, let's also remove pointless cast of the driver data.

> Cc: Bin Liu <binmlist@gmail.com>
> Cc: Brian Hutchinson <b.hutchman@gmail.com>
> Cc: George Cherian <george.cherian@ti.com>
> Signed-off-by: Tony Lindgren <tony@atomide.com>
> ---
>   drivers/usb/musb/musb_dsps.c | 37 ++++++++++++++++++++++++++++++++++++-
>   1 file changed, 36 insertions(+), 1 deletion(-)

> --- a/drivers/usb/musb/musb_dsps.c
> +++ b/drivers/usb/musb/musb_dsps.c
> @@ -655,6 +655,36 @@ static int dsps_musb_reset(struct musb *musb)
>   	return !session_restart;
>   }
>
> +/* Similar to am35x, dm81xx support only 32-bit read operation */
> +static void dsps_read_fifo32(struct musb_hw_ep *hw_ep, u16 len, u8 *dst)
> +{
> +	void __iomem *fifo = hw_ep->fifo;
> +	u32		val;
> +	int		i;
> +
> +	/* Read for 32bit-aligned destination address */
> +	if (likely((0x03 & (unsigned long)dst) == 0) && len >= 4) {
> +		readsl(fifo, dst, len >> 2);
> +		dst += len & ~0x03;
> +		len &= 0x03;
> +	}
> +	/*
> +	 * Now read the remaining 1 to 3 byte or complete length if
> +	 * unaligned address.
> +	 */

   This comment seems misplaced, it belongs before the next *if*.

> +	if (len > 4) {
> +		for (i = 0; i < (len >> 2); i++) {
> +			*(u32 *)dst = musb_readl(fifo, 0);
> +			dst += 4;
> +		}

    Not sure how this is different to using readsl().

> +		len &= 0x03;
> +	}
> +	if (len > 0) {
> +		val = musb_readl(fifo, 0);
> +		memcpy(dst, &val, len);
> +	}
> +}
> +
>   static struct musb_platform_ops dsps_ops = {
>   	.quirks		= MUSB_INDEXED_EP,
>   	.init		= dsps_musb_init,
[...]

WBR, Sergei

Re: [PATCH] usb: musb: Fix fifo reads for dm816x with musb_dsps

[Tony Lindgren]

* Sergei Shtylyov <sergei.shtylyov-M4DtvfQ/ZS1MRgGoP+s0PdBPR1lH4CV8@public.gmane.org> [150319 06:30]:
> On 3/19/2015 1:48 AM, Tony Lindgren wrote:
> 
> >Looks like dm81xx can only do 32-bit fifo reads like am35x. Let's set
> >up musb-dsps with a custom read_fifo function based on the compatible
> >flag.
...
> >--- a/drivers/usb/musb/musb_dsps.c
> >+++ b/drivers/usb/musb/musb_dsps.c
> >+/* Similar to am35x, dm81xx support only 32-bit read operation */
> >+static void dsps_read_fifo32(struct musb_hw_ep *hw_ep, u16 len, u8 *dst)
> >+{
> >+	void __iomem *fifo = hw_ep->fifo;
> >+	u32		val;
> >+	int		i;
> >+
> >+	/* Read for 32bit-aligned destination address */
> >+	if (likely((0x03 & (unsigned long)dst) == 0) && len >= 4) {
> >+		readsl(fifo, dst, len >> 2);
> >+		dst += len & ~0x03;
> >+		len &= 0x03;
> >+	}
> >+	/*
> >+	 * Now read the remaining 1 to 3 byte or complete length if
> >+	 * unaligned address.
> >+	 */
> 
>   This comment seems misplaced, it belongs before the next *if*.
> 
> >+	if (len > 4) {
> >+		for (i = 0; i < (len >> 2); i++) {
> >+			*(u32 *)dst = musb_readl(fifo, 0);
> >+			dst += 4;
> >+		}
> 
>    Not sure how this is different to using readsl().
> 
> >+		len &= 0x03;
> >+	}
> >+	if (len > 0) {
> >+		val = musb_readl(fifo, 0);
> >+		memcpy(dst, &val, len);
> >+	}
> >+}

Indeed, thanks for looking at it. That function in the TI kernel probably
had something else for the 32-bit aligned case that got swapped to use
readsl().

Looks like the following works just fine for me with a USB Ethernet
and variable size ping test:

static void dsps_read_fifo32(struct musb_hw_ep *hw_ep, u16 len, u8 *dst)
{
	void __iomem *fifo = hw_ep->fifo;

	if (len >= 4) {
		readsl(fifo, dst, len >> 2);
		dst += len & ~0x03;
		len &= 0x03;
	}

	/* Read any remaining 1 to 3 bytes */                                                                                
	if (len > 0) {
		u32 val = musb_readl(fifo, 0);
		memcpy(dst, &val, len);
	}
}

Regards,

Tony
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Re: [PATCH] usb: musb: Fix fifo reads for dm816x with musb_dsps

[Sergei Shtylyov]

On 03/19/2015 04:30 PM, Sergei Shtylyov wrote:

>> Looks like dm81xx can only do 32-bit fifo reads like am35x. Let's set
>> up musb-dsps with a custom read_fifo function based on the compatible
>> flag.

>> Otherwise we can get the following errors when starting dhclient on a
>> asix USB Ethernet adapter:

>> asix 2-1:1.0 eth2: asix_rx_fixup() Bad Header Length 0xffff003c, offset 4

>> While at it, let's also remove pointless cast of the driver data.

>> Cc: Bin Liu <binmlist-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
>> Cc: Brian Hutchinson <b.hutchman-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
>> Cc: George Cherian <george.cherian-l0cyMroinI0@public.gmane.org>
>> Signed-off-by: Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org>
>> ---
>>   drivers/usb/musb/musb_dsps.c | 37 ++++++++++++++++++++++++++++++++++++-
>>   1 file changed, 36 insertions(+), 1 deletion(-)

>> --- a/drivers/usb/musb/musb_dsps.c
>> +++ b/drivers/usb/musb/musb_dsps.c
>> @@ -655,6 +655,36 @@ static int dsps_musb_reset(struct musb *musb)
>>       return !session_restart;
>>   }
>>
>> +/* Similar to am35x, dm81xx support only 32-bit read operation */
>> +static void dsps_read_fifo32(struct musb_hw_ep *hw_ep, u16 len, u8 *dst)
>> +{
>> +    void __iomem *fifo = hw_ep->fifo;
>> +    u32        val;
>> +    int        i;
>> +
>> +    /* Read for 32bit-aligned destination address */
>> +    if (likely((0x03 & (unsigned long)dst) == 0) && len >= 4) {
>> +        readsl(fifo, dst, len >> 2);
>> +        dst += len & ~0x03;
>> +        len &= 0x03;
>> +    }
>> +    /*
>> +     * Now read the remaining 1 to 3 byte or complete length if
>> +     * unaligned address.
>> +     */

>    This comment seems misplaced, it belongs before the next *if*.

>> +    if (len > 4) {
>> +        for (i = 0; i < (len >> 2); i++) {
>> +            *(u32 *)dst = musb_readl(fifo, 0);
>> +            dst += 4;
>> +        }

>     Not sure how this is different to using readsl().

    Ah, the default implementation of musb_readl() uses __raw_readl().
So you'd probably want to keep this loop, not readsl() call.

>> +        len &= 0x03;
>> +    }
>> +    if (len > 0) {
>> +        val = musb_readl(fifo, 0);
>> +        memcpy(dst, &val, len);
>> +    }
>> +}
>> +
>>   static struct musb_platform_ops dsps_ops = {
>>       .quirks        = MUSB_INDEXED_EP,
>>       .init        = dsps_musb_init,
[...]

WBR, Sergei

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Re: [PATCH] usb: musb: Fix fifo reads for dm816x with musb_dsps

[Tony Lindgren]

* Sergei Shtylyov <sergei.shtylyov-M4DtvfQ/ZS1MRgGoP+s0PdBPR1lH4CV8@public.gmane.org> [150319 10:50]:
> On 03/19/2015 04:30 PM, Sergei Shtylyov wrote:
> >>--- a/drivers/usb/musb/musb_dsps.c
> >>+++ b/drivers/usb/musb/musb_dsps.c
> >>@@ -655,6 +655,36 @@ static int dsps_musb_reset(struct musb *musb)
> >>      return !session_restart;
> >>  }
> >>
> >>+/* Similar to am35x, dm81xx support only 32-bit read operation */
> >>+static void dsps_read_fifo32(struct musb_hw_ep *hw_ep, u16 len, u8 *dst)
> >>+{
> >>+    void __iomem *fifo = hw_ep->fifo;
> >>+    u32        val;
> >>+    int        i;
> >>+
> >>+    /* Read for 32bit-aligned destination address */
> >>+    if (likely((0x03 & (unsigned long)dst) == 0) && len >= 4) {
> >>+        readsl(fifo, dst, len >> 2);
> >>+        dst += len & ~0x03;
> >>+        len &= 0x03;
> >>+    }
> >>+    /*
> >>+     * Now read the remaining 1 to 3 byte or complete length if
> >>+     * unaligned address.
> >>+     */
> 
> >   This comment seems misplaced, it belongs before the next *if*.
> 
> >>+    if (len > 4) {
> >>+        for (i = 0; i < (len >> 2); i++) {
> >>+            *(u32 *)dst = musb_readl(fifo, 0);
> >>+            dst += 4;
> >>+        }
> 
> >    Not sure how this is different to using readsl().
> 
>    Ah, the default implementation of musb_readl() uses __raw_readl().
> So you'd probably want to keep this loop, not readsl() call.

Not sure I follow you here.. Also include/asm-generic/io.h readsl()
uses __raw_readl()?

It seems things work with what I posted, so a readsl() loop, then
just read the remaining 1 to 3 bytes.

Regards,

Tony 
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Re: [PATCH] usb: musb: Fix fifo reads for dm816x with musb_dsps

[Sergei Shtylyov]

On 03/19/2015 08:55 PM, Tony Lindgren wrote:

>>>> --- a/drivers/usb/musb/musb_dsps.c
>>>> +++ b/drivers/usb/musb/musb_dsps.c
>>>> @@ -655,6 +655,36 @@ static int dsps_musb_reset(struct musb *musb)
>>>>       return !session_restart;
>>>>   }
>>>>
>>>> +/* Similar to am35x, dm81xx support only 32-bit read operation */
>>>> +static void dsps_read_fifo32(struct musb_hw_ep *hw_ep, u16 len, u8 *dst)
>>>> +{
>>>> +    void __iomem *fifo = hw_ep->fifo;
>>>> +    u32        val;
>>>> +    int        i;
>>>> +
>>>> +    /* Read for 32bit-aligned destination address */
>>>> +    if (likely((0x03 & (unsigned long)dst) == 0) && len >= 4) {
>>>> +        readsl(fifo, dst, len >> 2);
>>>> +        dst += len & ~0x03;
>>>> +        len &= 0x03;
>>>> +    }
>>>> +    /*
>>>> +     * Now read the remaining 1 to 3 byte or complete length if
>>>> +     * unaligned address.
>>>> +     */

>>>    This comment seems misplaced, it belongs before the next *if*.

>>>> +    if (len > 4) {
>>>> +        for (i = 0; i < (len >> 2); i++) {
>>>> +            *(u32 *)dst = musb_readl(fifo, 0);
>>>> +            dst += 4;
>>>> +        }

>>>     Not sure how this is different to using readsl().

>>     Ah, the default implementation of musb_readl() uses __raw_readl().
>> So you'd probably want to keep this loop, not readsl() call.

> Not sure I follow you here..

    I just wrongly thought readsl() uses readl() internally. readl() is 
supposed to swap bytes when needed (BE case), while __raw_readl() is not.

> Also include/asm-generic/io.h readsl()
> uses __raw_readl()?

    Looking at the arch/arm/include/asm/io.h, readsl() is equivalent to 
__raw_readsl() too. Forgot about this "asymmetry".

> It seems things work with what I posted, so a readsl() loop, then
> just read the remaining 1 to 3 bytes.

    In LE mode, there would have been no difference anyway.

> Regards,

> Tony

WBR, Sergei

Re: [PATCH] usb: musb: Fix fifo reads for dm816x with musb_dsps

[Andrew Morton]

On Wed, 18 Mar 2015 15:48:02 -0700 Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org> wrote:

> Looks like dm81xx can only do 32-bit fifo reads like am35x. Let's set
> up musb-dsps with a custom read_fifo function based on the compatible
> flag.
> 
> Otherwise we can get the following errors when starting dhclient on a
> asix USB Ethernet adapter:
> 
> asix 2-1:1.0 eth2: asix_rx_fixup() Bad Header Length 0xffff003c, offset 4
> 
> While at it, let's also remove pointless cast of the driver data.

This breaks my i386 allmodconfig build.

> +/* Similar to am35x, dm81xx support only 32-bit read operation */
> +static void dsps_read_fifo32(struct musb_hw_ep *hw_ep, u16 len, u8 *dst)
> +{
> +	void __iomem *fifo = hw_ep->fifo;
> +	u32		val;
> +	int		i;
> +
> +	/* Read for 32bit-aligned destination address */
> +	if (likely((0x03 & (unsigned long)dst) == 0) && len >= 4) {
> +		readsl(fifo, dst, len >> 2);

akpm3:/usr/src/linux-4.0-rc6> grep -r readsl arch/x86 
akpm3:/usr/src/linux-4.0-rc6> 

> +		dst += len & ~0x03;
> +		len &= 0x03;
> +	}
> +	/*
> +	 * Now read the remaining 1 to 3 byte or complete length if
> +	 * unaligned address.
> +	 */
> +	if (len > 4) {
> +		for (i = 0; i < (len >> 2); i++) {
> +			*(u32 *)dst = musb_readl(fifo, 0);
> +			dst += 4;
> +		}
> +		len &= 0x03;
> +	}
> +	if (len > 0) {
> +		val = musb_readl(fifo, 0);
> +		memcpy(dst, &val, len);
> +	}
> +}

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Re: [PATCH] usb: musb: Fix fifo reads for dm816x with musb_dsps

[Tony Lindgren]

* Andrew Morton <akpm@linux-foundation.org> [150401 14:36]:
> On Wed, 18 Mar 2015 15:48:02 -0700 Tony Lindgren <tony@atomide.com> wrote:
> 
> > Looks like dm81xx can only do 32-bit fifo reads like am35x. Let's set
> > up musb-dsps with a custom read_fifo function based on the compatible
> > flag.
> > 
> > Otherwise we can get the following errors when starting dhclient on a
> > asix USB Ethernet adapter:
> > 
> > asix 2-1:1.0 eth2: asix_rx_fixup() Bad Header Length 0xffff003c, offset 4
> > 
> > While at it, let's also remove pointless cast of the driver data.
> 
> This breaks my i386 allmodconfig build.
> 
> > +/* Similar to am35x, dm81xx support only 32-bit read operation */
> > +static void dsps_read_fifo32(struct musb_hw_ep *hw_ep, u16 len, u8 *dst)
> > +{
> > +	void __iomem *fifo = hw_ep->fifo;
> > +	u32		val;
> > +	int		i;
> > +
> > +	/* Read for 32bit-aligned destination address */
> > +	if (likely((0x03 & (unsigned long)dst) == 0) && len >= 4) {
> > +		readsl(fifo, dst, len >> 2);
> 
> akpm3:/usr/src/linux-4.0-rc6> grep -r readsl arch/x86 
> akpm3:/usr/src/linux-4.0-rc6> 

Yes sorry, the fix is to use ioread32_rep() instead. I already sent a fix
for that on the 25th as:

"[PATCH 1/1] usb: musb: dsps: fix build on i386 when COMPILE_TEST is set"

https://www.marc.info/?l=linux-usb&m=142731859732737&w=1

Felipe, can you please get that into Linux next?

Regards,

Tony