From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 282D614038F; Fri, 21 Jun 2024 07:09:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718953747; cv=none; b=mLXG5MYF7WDl0q1SVJyByXeBP0+VJP6IYm9I/lJq/0hU98Rte4bTw+44OofLca/TDCh28vJMLD/+JnEu5xrXazLmVgOgpsKIRIJ6rGnKkGRW7iWO1ToRJ4oVswTIytjNZluVUei3KKDVYXb2gimX/SHgUEiAjgf6xvzIhjy6rxw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718953747; c=relaxed/simple; bh=JNeSznPsu6rMM8q9i1YN4cUCJ34wg5WxXaxe2u+XauI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=LYGEkNJKZc0QHUQepdlBsIXSPEfEB3cTOKiTeQfxEpoUYTsHPwGX/f6Z48VqpsSf/W5KiP4AV1Q9dOw/qTyGi/Ndg+HRy+CLhLkVJCZM5PwTQc3XZd5XTFysY7+lr+0FfhKP+P+5upJoUFArZ7LcG4OiBUybphZImBDfeyfYtAs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=YuiNfFBj; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="YuiNfFBj" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 522EBC2BBFC; Fri, 21 Jun 2024 07:09:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1718953746; bh=JNeSznPsu6rMM8q9i1YN4cUCJ34wg5WxXaxe2u+XauI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=YuiNfFBjYQZ4LWbVZN2X73hS5tUPBXHgfp6QswTqOZ2KDQNS6n7gypHuB7O9Ltu5l btpKVynQuyMi1uu5NaLbZzYltuiNLZoYU/ya58uhWbgtzPeJf7s6FrsaSqhBSNKVta 8AB9fKEKDbvJHvK/anMsronwVvkEkcxdaDOw0rcQ= Date: Fri, 21 Jun 2024 09:09:03 +0200 From: Greg KH To: Thinh Nguyen Cc: joswang , "linux-usb@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" , Jos Wang Subject: Re: [PATCH v7] usb: dwc3: core: Workaround for CSR read timeout Message-ID: <2024062126-whacky-employee-74a4@gregkh> References: <20240619114529.3441-1-joswang1221@gmail.com> <2024062051-washtub-sufferer-d756@gregkh> <2024062151-professor-squeak-a4a7@gregkh> <20240621054239.mskjqbuhovydvmu4@synopsys.com> <2024062150-justify-skillet-e80e@gregkh> <20240621062036.2rhksldny7dzijv2@synopsys.com> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20240621062036.2rhksldny7dzijv2@synopsys.com> On Fri, Jun 21, 2024 at 06:20:38AM +0000, Thinh Nguyen wrote: > On Fri, Jun 21, 2024, Greg KH wrote: > > On Fri, Jun 21, 2024 at 05:42:42AM +0000, Thinh Nguyen wrote: > > > On Fri, Jun 21, 2024, Greg KH wrote: > > > > On Fri, Jun 21, 2024 at 09:40:10AM +0800, joswang wrote: > > > > > On Fri, Jun 21, 2024 at 1:16 AM Greg KH wrote: > > > > > > > > > > > > On Wed, Jun 19, 2024 at 07:45:29PM +0800, joswang wrote: > > > > > > > From: Jos Wang > > > > > > > > > > > > > > This is a workaround for STAR 4846132, which only affects > > > > > > > DWC_usb31 version2.00a operating in host mode. > > > > > > > > > > > > > > There is a problem in DWC_usb31 version 2.00a operating > > > > > > > in host mode that would cause a CSR read timeout When CSR > > > > > > > read coincides with RAM Clock Gating Entry. By disable > > > > > > > Clock Gating, sacrificing power consumption for normal > > > > > > > operation. > > > > > > > > > > > > > > Cc: stable@vger.kernel.org > > > > > > > Signed-off-by: Jos Wang > > > > > > > > > > > > What commit id does this fix? How far back should it be backported in > > > > > > the stable releases? > > > > > > > > > > > > thanks, > > > > > > > > > > > > greg k-h > > > > > > > > > > Hello Greg Thinh > > > > > > > > > > It seems first begin from the commit 1e43c86d84fb ("usb: dwc3: core: > > > > > Add DWC31 version 2.00a controller") > > > > > in 6.8.0-rc6 branch ? > > > > > > > > That commit showed up in 6.9, not 6.8. And if so, please resend with a > > > > proper "Fixes:" tag. > > > > > > > > > > This patch workarounds the controller's issue. > > > > So it fixes a bug? Or does not fix a bug? I'm confused. > > The bug is not a driver's bug. The fix applies to a hardware bug and not > any particular commit that can be referenced with a "Fixes" tag. So it's a bug that the kernel needs to work around, that's fine. But that implies it should go to "all" stable kernels that it can, right? > > > It doesn't resolve any > > > particular commit that requires a "Fixes" tag. So, this should go on > > > "next". It can be backported as needed. > > > > Who would do the backporting and when? > > For anyone who doesn't use mainline kernel that needs this patch > backported to their kernel version. I can not poarse this, sorry. We can't do anything about people who don't use our kernel trees, so what does this mean? > > > If it's to be backported, it can > > > probably go back to as far as v4.3, to commit 690fb3718a70 ("usb: dwc3: > > > Support Synopsys USB 3.1 IP"). But you'd need to collect all the > > > dependencies including the commit mention above. > > > > I don't understand, sorry. Is this just a normal "evolve the driver to > > work better" change, or is it a "fix broken code" change, or is it > > something else? > > > > In other words, what do you want to see happen to this? What tree(s) > > would you want it applied to? > > > > It's up to you, but it seems to fit "usb-testing" branch more since it > doesn't have a "Fixes" tag. The severity of this fix is debatable since > it doesn't apply to every DWC_usb31 configuration or every scenario. As it is "cc: stable" that implies that it should get to Linus for 6.10-final, not wait for 6.11-rc1 as the 6.11 release is months away, and anyone who has this issue would want it fixed sooner. still confused, greg k-h