From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Osipenko Subject: Re: [PATCH v1] usb: phy: tegra: Add clarifying comments about the shared registers Date: Mon, 3 Feb 2020 19:26:04 +0300 Message-ID: <5a8d6489-e8ce-5a6e-3e23-8de97c3bad76@gmail.com> References: <20200202224259.29187-1-digetx@gmail.com> <20200203112818.GA3506060@ulmo> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20200203112818.GA3506060@ulmo> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Thierry Reding Cc: Greg Kroah-Hartman , Jonathan Hunter , Felipe Balbi , linux-usb@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-tegra@vger.kernel.org 03.02.2020 14:28, Thierry Reding пишет: > On Mon, Feb 03, 2020 at 01:42:59AM +0300, Dmitry Osipenko wrote: >> Tools like Coccinelle may erroneously recommend to use the >> devm_platform_ioremap_resource() API for the registers mapping because >> these tools are not aware about the implementation details of the driver. >> Let's add a clarifying comments to the code, which should help to stop >> future attempts to break the driver. >> >> Signed-off-by: Dmitry Osipenko >> --- >> drivers/usb/phy/phy-tegra-usb.c | 8 ++++++++ >> 1 file changed, 8 insertions(+) >> >> diff --git a/drivers/usb/phy/phy-tegra-usb.c b/drivers/usb/phy/phy-tegra-usb.c >> index 037e8eee737d..6153cc35aba0 100644 >> --- a/drivers/usb/phy/phy-tegra-usb.c >> +++ b/drivers/usb/phy/phy-tegra-usb.c >> @@ -969,6 +969,10 @@ static int utmi_phy_probe(struct tegra_usb_phy *tegra_phy, >> return -ENXIO; >> } >> >> + /* >> + * Note that UTMI pad registers are shared by all PHYs, therefore >> + * devm_platform_ioremap_resource() can't be used here. >> + */ >> tegra_phy->pad_regs = devm_ioremap(&pdev->dev, res->start, >> resource_size(res)); >> if (!tegra_phy->pad_regs) { >> @@ -1087,6 +1091,10 @@ static int tegra_usb_phy_probe(struct platform_device *pdev) >> return -ENXIO; >> } >> >> + /* >> + * Note that PHY and USB controller are using shared registers, >> + * therefore devm_platform_ioremap_resource() can't be used here. >> + */ >> tegra_phy->regs = devm_ioremap(&pdev->dev, res->start, >> resource_size(res)); >> if (!tegra_phy->regs) { > > I'm not sure it's really going to stop *all* attempts. But at least for > people that go through the trouble of reading the comments, yes, this > should do the trick, so: > > Acked-by: Thierry Reding Will see, thanks :)