Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
To:     Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc:     Nicolas.Ferre@microchip.com, wg@grandegger.com, mkl@pengutronix.de,
        davem@davemloft.net, Ludovic.Desroches@microchip.com,
        linux-can@vger.kernel.org, netdev@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        Kees Cook <keescook@chromium.org>
References: <20190129180612.GA28650@embeddedor>
 <432a9399-95f4-e988-5cd2-93340f155fa1@microchip.com>
 <daae008e-35fd-7553-fcb2-7932fe53b959@embeddedor.com>
 <20190214221703.GQ10129@piout.net>
From:   "Gustavo A. R. Silva" <gustavo@embeddedor.com>
Openpgp: preference=signencrypt
Autocrypt: addr=gustavo@embeddedor.com; keydata=
 mQINBFssHAwBEADIy3ZoPq3z5UpsUknd2v+IQud4TMJnJLTeXgTf4biSDSrXn73JQgsISBwG
 2Pm4wnOyEgYUyJd5tRWcIbsURAgei918mck3tugT7AQiTUN3/5aAzqe/4ApDUC+uWNkpNnSV
 tjOx1hBpla0ifywy4bvFobwSh5/I3qohxDx+c1obd8Bp/B/iaOtnq0inli/8rlvKO9hp6Z4e
 DXL3PlD0QsLSc27AkwzLEc/D3ZaqBq7ItvT9Pyg0z3Q+2dtLF00f9+663HVC2EUgP25J3xDd
 496SIeYDTkEgbJ7WYR0HYm9uirSET3lDqOVh1xPqoy+U9zTtuA9NQHVGk+hPcoazSqEtLGBk
 YE2mm2wzX5q2uoyptseSNceJ+HE9L+z1KlWW63HhddgtRGhbP8pj42bKaUSrrfDUsicfeJf6
 m1iJRu0SXYVlMruGUB1PvZQ3O7TsVfAGCv85pFipdgk8KQnlRFkYhUjLft0u7CL1rDGZWDDr
 NaNj54q2CX9zuSxBn9XDXvGKyzKEZ4NY1Jfw+TAMPCp4buawuOsjONi2X0DfivFY+ZsjAIcx
 qQMglPtKk/wBs7q2lvJ+pHpgvLhLZyGqzAvKM1sVtRJ5j+ARKA0w4pYs5a5ufqcfT7dN6TBk
 LXZeD9xlVic93Ju08JSUx2ozlcfxq+BVNyA+dtv7elXUZ2DrYwARAQABtCxHdXN0YXZvIEEu
 IFIuIFNpbHZhIDxndXN0YXZvQGVtYmVkZGVkb3IuY29tPokCPQQTAQgAJwUCWywcDAIbIwUJ
 CWYBgAULCQgHAgYVCAkKCwIEFgIDAQIeAQIXgAAKCRBHBbTLRwbbMZ6tEACk0hmmZ2FWL1Xi
 l/bPqDGFhzzexrdkXSfTTZjBV3a+4hIOe+jl6Rci/CvRicNW4H9yJHKBrqwwWm9fvKqOBAg9
 obq753jydVmLwlXO7xjcfyfcMWyx9QdYLERTeQfDAfRqxir3xMeOiZwgQ6dzX3JjOXs6jHBP
 cgry90aWbaMpQRRhaAKeAS14EEe9TSIly5JepaHoVdASuxklvOC0VB0OwNblVSR2S5i5hSsh
 ewbOJtwSlonsYEj4EW1noQNSxnN/vKuvUNegMe+LTtnbbocFQ7dGMsT3kbYNIyIsp42B5eCu
 JXnyKLih7rSGBtPgJ540CjoPBkw2mCfhj2p5fElRJn1tcX2McsjzLFY5jK9RYFDavez5w3lx
 JFgFkla6sQHcrxH62gTkb9sUtNfXKucAfjjCMJ0iuQIHRbMYCa9v2YEymc0k0RvYr43GkA3N
 PJYd/vf9vU7VtZXaY4a/dz1d9dwIpyQARFQpSyvt++R74S78eY/+lX8wEznQdmRQ27kq7BJS
 R20KI/8knhUNUJR3epJu2YFT/JwHbRYC4BoIqWl+uNvDf+lUlI/D1wP+lCBSGr2LTkQRoU8U
 64iK28BmjJh2K3WHmInC1hbUucWT7Swz/+6+FCuHzap/cjuzRN04Z3Fdj084oeUNpP6+b9yW
 e5YnLxF8ctRAp7K4yVlvA7kCDQRbLBwMARAAsHCE31Ffrm6uig1BQplxMV8WnRBiZqbbsVJB
 H1AAh8tq2ULl7udfQo1bsPLGGQboJSVN9rckQQNahvHAIK8ZGfU4Qj8+CER+fYPp/MDZj+t0
 DbnWSOrG7z9HIZo6PR9z4JZza3Hn/35jFggaqBtuydHwwBANZ7A6DVY+W0COEU4of7CAahQo
 5NwYiwS0lGisLTqks5R0Vh+QpvDVfuaF6I8LUgQR/cSgLkR//V1uCEQYzhsoiJ3zc1HSRyOP
 otJTApqGBq80X0aCVj1LOiOF4rrdvQnj6iIlXQssdb+WhSYHeuJj1wD0ZlC7ds5zovXh+FfF
 l5qH5RFY/qVn3mNIVxeO987WSF0jh+T5ZlvUNdhedGndRmwFTxq2Li6GNMaolgnpO/CPcFpD
 jKxY/HBUSmaE9rNdAa1fCd4RsKLlhXda+IWpJZMHlmIKY8dlUybP+2qDzP2lY7kdFgPZRU+e
 zS/pzC/YTzAvCWM3tDgwoSl17vnZCr8wn2/1rKkcLvTDgiJLPCevqpTb6KFtZosQ02EGMuHQ
 I6Zk91jbx96nrdsSdBLGH3hbvLvjZm3C+fNlVb9uvWbdznObqcJxSH3SGOZ7kCHuVmXUcqoz
 ol6ioMHMb+InrHPP16aVDTBTPEGwgxXI38f7SUEn+NpbizWdLNz2hc907DvoPm6HEGCanpcA
 EQEAAYkCJQQYAQgADwUCWywcDAIbDAUJCWYBgAAKCRBHBbTLRwbbMdsZEACUjmsJx2CAY+QS
 UMebQRFjKavwXB/xE7fTt2ahuhHT8qQ/lWuRQedg4baInw9nhoPE+VenOzhGeGlsJ0Ys52sd
 XvUjUocKgUQq6ekOHbcw919nO5L9J2ejMf/VC/quN3r3xijgRtmuuwZjmmi8ct24TpGeoBK4
 WrZGh/1hAYw4ieARvKvgjXRstcEqM5thUNkOOIheud/VpY+48QcccPKbngy//zNJWKbRbeVn
 imua0OpqRXhCrEVm/xomeOvl1WK1BVO7z8DjSdEBGzbV76sPDJb/fw+y+VWrkEiddD/9CSfg
 fBNOb1p1jVnT2mFgGneIWbU0zdDGhleI9UoQTr0e0b/7TU+Jo6TqwosP9nbk5hXw6uR5k5PF
 8ieyHVq3qatJ9K1jPkBr8YWtI5uNwJJjTKIA1jHlj8McROroxMdI6qZ/wZ1ImuylpJuJwCDC
 ORYf5kW61fcrHEDlIvGc371OOvw6ejF8ksX5+L2zwh43l/pKkSVGFpxtMV6d6J3eqwTafL86
 YJWH93PN+ZUh6i6Rd2U/i8jH5WvzR57UeWxE4P8bQc0hNGrUsHQH6bpHV2lbuhDdqo+cM9eh
 GZEO3+gCDFmKrjspZjkJbB5Gadzvts5fcWGOXEvuT8uQSvl+vEL0g6vczsyPBtqoBLa9SNrS
 VtSixD1uOgytAP7RWS474w==
Subject: Re: [PATCH] can: mark expected switch fall-throughs
Message-ID: <a8e53868-2b13-b050-7714-e3e24d18cf00@embeddedor.com>
Date:   Thu, 14 Feb 2019 17:04:03 -0600
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101
 Thunderbird/60.4.0
MIME-Version: 1.0
In-Reply-To: <20190214221703.GQ10129@piout.net>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk


On 2/14/19 4:17 PM, Alexandre Belloni wrote:
> Hi,
> 
> On 14/02/2019 15:37:26-0600, Gustavo A. R. Silva wrote:
>>
>>
>> On 1/30/19 2:11 AM, Nicolas.Ferre@microchip.com wrote:
>>> On 29/01/2019 at 19:06, Gustavo A. R. Silva wrote:
>>>> In preparation to enabling -Wimplicit-fallthrough, mark switch cases
>>>> where we are expecting to fall through.
>>>>
>>>> This patch fixes the following warnings:
>>>>
>>>> drivers/net/can/peak_canfd/peak_pciefd_main.c:668:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
>>>> drivers/net/can/spi/mcp251x.c:875:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
>>>> drivers/net/can/usb/peak_usb/pcan_usb.c:422:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
>>>> drivers/net/can/at91_can.c:895:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
>>>> drivers/net/can/at91_can.c:953:15: warning: this statement may fall through [-Wimplicit-fallthrough=]
>>>> drivers/net/can/usb/peak_usb/pcan_usb.c: In function ‘pcan_usb_decode_error’:
>>>> drivers/net/can/usb/peak_usb/pcan_usb.c:422:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
>>>>     if (n & PCAN_USB_ERROR_BUS_LIGHT) {
>>>>        ^
>>>> drivers/net/can/usb/peak_usb/pcan_usb.c:428:2: note: here
>>>>    case CAN_STATE_ERROR_WARNING:
>>>>    ^~~~
>>>>
>>>> Warning level 3 was used: -Wimplicit-fallthrough=3
>>>>
>>>> This patch is part of the ongoing efforts to enabling
>>>> -Wimplicit-fallthrough.
>>>>
>>>> Notice that in some cases spelling mistakes were fixed.
>>>> In other cases, the /* fall through */ comment is placed
>>>> at the bottom of the case statement, which is what GCC
>>>> is expecting to find.
>>>>
>>>> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
>>>> ---
>>>>   drivers/net/can/at91_can.c                    | 6 ++++--
>>>
>>> For this one:
>>> Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
>>>
>>
>> Thanks, Nicolas.
>>
> 
> I though I had a déjà vu but you actually sent the at91 part twice.
> 

It wasn't intentional.

>> Dave:
>>
>> I wonder if you can take this patch.
>>
>> Thanks
>> --
>> Gustavo
>>
>>>>   drivers/net/can/peak_canfd/peak_pciefd_main.c | 2 +-
>>>>   drivers/net/can/spi/mcp251x.c                 | 3 ++-
>>>>   drivers/net/can/usb/peak_usb/pcan_usb.c       | 2 +-
>>>>   4 files changed, 8 insertions(+), 5 deletions(-)
>>>>
>>>> diff --git a/drivers/net/can/at91_can.c b/drivers/net/can/at91_can.c
>>>> index d98c69045b17..1718c20f9c99 100644
>>>> --- a/drivers/net/can/at91_can.c
>>>> +++ b/drivers/net/can/at91_can.c
>>>> @@ -902,7 +902,8 @@ static void at91_irq_err_state(struct net_device *dev,
>>>>   				CAN_ERR_CRTL_TX_WARNING :
>>>>   				CAN_ERR_CRTL_RX_WARNING;
>>>>   		}
>>>> -	case CAN_STATE_ERROR_WARNING:	/* fallthrough */
>>>> +		/* fall through */
>>>> +	case CAN_STATE_ERROR_WARNING:
>>>>   		/*
>>>>   		 * from: ERROR_ACTIVE, ERROR_WARNING
>>>>   		 * to  : ERROR_PASSIVE, BUS_OFF
>>>> @@ -951,7 +952,8 @@ static void at91_irq_err_state(struct net_device *dev,
>>>>   		netdev_dbg(dev, "Error Active\n");
>>>>   		cf->can_id |= CAN_ERR_PROT;
>>>>   		cf->data[2] = CAN_ERR_PROT_ACTIVE;
>>>> -	case CAN_STATE_ERROR_WARNING:	/* fallthrough */
> 
> Seriously, for that one, you should fix the compiler. The fall through

I'll pass your feedback on to the GCC guys.

> is not implicit, it is actually quite explicit and the warning is simply
> wrong.
> 
> Also, the gcc documentation says that -Wimplicit-fallthrough=3
> recognizes /* fallthrough */ as a proper fall through comment (and I
> tested with gcc 8.2).
> 

Yeah. But that's not the relevant change in this case.  Notice that the
comment was moved to the very bottom of the previous case.

Thanks
--
Gustavo