[PATCH] MUSB: Fix index register corruption seen with g_ether and Windows host

[PATCH] MUSB: Fix index register corruption seen with g_ether and Windows host

[Gadiyar, Anand]

From: Anand Gadiyar <gadiyar@ti.com>

If Indexed Mode register accesses are enabled, the ep0_rxstate()
function calls musb_g_ep0_giveback() before writing to the CSR
register. When control returns to this ep0_rxstate, the index
register contents are over-written. This causes the CSR register
write to fail.

Fixed by writing the correct value into the index register before
writing to the CSR.

This was observed only in ep0_rxstate() with g_ether loaded and
the device connected to a MS Windows host PC. Anticipatively fixed
ep0_txstate() as well.

Signed-off-by: Anand Gadiyar <gadiyar@ti.com>
---
Fixed my mailer finally. :)

 drivers/usb/musb/musb_gadget_ep0.c |    2 ++
 1 files changed, 2 insertions(+)

Index: linux-omap-2.6/drivers/usb/musb/musb_gadget_ep0.c
===================================================================
--- linux-omap-2.6.orig/drivers/usb/musb/musb_gadget_ep0.c	2008-04-14 15:36:38.000000000 +0530
+++ linux-omap-2.6/drivers/usb/musb/musb_gadget_ep0.c	2008-08-21 18:12:11.688711634 +0530
@@ -476,6 +476,7 @@ static void ep0_rxstate(struct musb *mus
 			return;
 		musb->ackpend = 0;
 	}
+	musb_ep_select(musb->mregs, 0);
 	musb_writew(regs, MUSB_CSR0, tmp);
 }
 
@@ -528,6 +529,7 @@ static void ep0_txstate(struct musb *mus
 	}
 
 	/* send it out, triggering a "txpktrdy cleared" irq */
+	musb_ep_select(musb->mregs, 0);
 	musb_writew(regs, MUSB_CSR0, csr);
 }
 

Re: [PATCH] MUSB: Fix index register corruption seen with g_ether and Windows host

[Felipe Balbi]

On Thu, Aug 21, 2008 at 08:21:00PM +0530, ext Gadiyar, Anand wrote:
> From: Anand Gadiyar <gadiyar-l0cyMroinI0@public.gmane.org>
> 
> If Indexed Mode register accesses are enabled, the ep0_rxstate()
> function calls musb_g_ep0_giveback() before writing to the CSR
> register. When control returns to this ep0_rxstate, the index
> register contents are over-written. This causes the CSR register
> write to fail.
> 
> Fixed by writing the correct value into the index register before
> writing to the CSR.
> 
> This was observed only in ep0_rxstate() with g_ether loaded and
> the device connected to a MS Windows host PC. Anticipatively fixed
> ep0_txstate() as well.
> 
> Signed-off-by: Anand Gadiyar <gadiyar-l0cyMroinI0@public.gmane.org>

Acked-by: Felipe Balbi <felipe.balbi-xNZwKgViW5gAvxtiuMwx3w@public.gmane.org>

> Fixed my mailer finally. :)

good :-)

> 
>  drivers/usb/musb/musb_gadget_ep0.c |    2 ++
>  1 files changed, 2 insertions(+)
> 
> Index: linux-omap-2.6/drivers/usb/musb/musb_gadget_ep0.c
> ===================================================================
> --- linux-omap-2.6.orig/drivers/usb/musb/musb_gadget_ep0.c	2008-04-14 15:36:38.000000000 +0530
> +++ linux-omap-2.6/drivers/usb/musb/musb_gadget_ep0.c	2008-08-21 18:12:11.688711634 +0530
> @@ -476,6 +476,7 @@ static void ep0_rxstate(struct musb *mus
>  			return;
>  		musb->ackpend = 0;
>  	}
> +	musb_ep_select(musb->mregs, 0);
>  	musb_writew(regs, MUSB_CSR0, tmp);
>  }
>  
> @@ -528,6 +529,7 @@ static void ep0_txstate(struct musb *mus
>  	}
>  
>  	/* send it out, triggering a "txpktrdy cleared" irq */
> +	musb_ep_select(musb->mregs, 0);
>  	musb_writew(regs, MUSB_CSR0, csr);
>  }
>  
-- 
balbi
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patch musb-fix-index-register-corruption-seen-with-g_ether-and-windows-host.patch added to gregkh-2.6 tree

[gregkh-l3A5Bk7waGM]

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

    Subject: MUSB: Fix index register corruption seen with g_ether and Windows host

to my gregkh-2.6 tree.  Its filename is

    musb-fix-index-register-corruption-seen-with-g_ether-and-windows-host.patch

This tree can be found at 
    http://www.kernel.org/pub/linux/kernel/people/gregkh/gregkh-2.6/patches/


>From gadiyar-l0cyMroinI0@public.gmane.org  Thu Aug 21 08:40:33 2008
From: "Gadiyar, Anand" <gadiyar-l0cyMroinI0@public.gmane.org>
Date: Thu, 21 Aug 2008 20:21:00 +0530
Subject: MUSB: Fix index register corruption seen with g_ether and Windows host
To: "greg-U8xfFu+wG4EAvxtiuMwx3w@public.gmane.org" <greg-U8xfFu+wG4EAvxtiuMwx3w@public.gmane.org>, "linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" <linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Cc: "linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" <linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>, "felipe.balbi-xNZwKgViW5gAvxtiuMwx3w@public.gmane.org" <felipe.balbi-xNZwKgViW5gAvxtiuMwx3w@public.gmane.org>, Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org>
Message-ID: <5A47E75E594F054BAF48C5E4FC4B92AB02C3E31565-/tLxBxkBPtCIQmiDNMet8wC/G2K4zDHf@public.gmane.org>


From: Anand Gadiyar <gadiyar-l0cyMroinI0@public.gmane.org>

If Indexed Mode register accesses are enabled, the ep0_rxstate()
function calls musb_g_ep0_giveback() before writing to the CSR
register. When control returns to this ep0_rxstate, the index
register contents are over-written. This causes the CSR register
write to fail.

Fixed by writing the correct value into the index register before
writing to the CSR.

This was observed only in ep0_rxstate() with g_ether loaded and
the device connected to a MS Windows host PC. Anticipatively fixed
ep0_txstate() as well.

Signed-off-by: Anand Gadiyar <gadiyar-l0cyMroinI0@public.gmane.org>
Acked-by: Felipe Balbi <felipe.balbi-xNZwKgViW5gAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Greg Kroah-Hartman <gregkh-l3A5Bk7waGM@public.gmane.org>

---
 drivers/usb/musb/musb_gadget_ep0.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/usb/musb/musb_gadget_ep0.c
+++ b/drivers/usb/musb/musb_gadget_ep0.c
@@ -476,6 +476,7 @@ static void ep0_rxstate(struct musb *mus
 			return;
 		musb->ackpend = 0;
 	}
+	musb_ep_select(musb->mregs, 0);
 	musb_writew(regs, MUSB_CSR0, tmp);
 }
 
@@ -528,6 +529,7 @@ static void ep0_txstate(struct musb *mus
 	}
 
 	/* send it out, triggering a "txpktrdy cleared" irq */
+	musb_ep_select(musb->mregs, 0);
 	musb_writew(regs, MUSB_CSR0, csr);
 }
 


Patches currently in gregkh-2.6 which might be from gadiyar-l0cyMroinI0@public.gmane.org are

usb.current/usb-musb-get-rid-of-musb_loglevel-and-use-parameter.patch
usb.current/usb-musb-get-rid-of-procfs-entry.patch
usb.current/musb-fix-index-register-corruption-seen-with-g_ether-and-windows-host.patch
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