Re: [PATCH] fpga: allow to compile-test Altera FPGA bridge drivers

From: Tobias Klauser
Date: Wed Apr 19 2017 - 08:08:04 EST

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In reply to: matthew . gerlach: "Re: [PATCH] fpga: allow to compile-test Altera FPGA bridge drivers"
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Hi Matthew

Thanks for the detailed analysis!

On 2017-04-18 at 17:27:15 +0200, matthew.gerlach@xxxxxxxxxxxxxxx <matthew.gerlach@xxxxxxxxxxxxxxx> wrote:

[...]

> >[auto build test WARNING on linus/master]
> >[also build test WARNING on v4.11-rc6 next-20170411]
> >[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
> >
> >url: https://github.com/0day-ci/linux/commits/Tobias-Klauser/fpga-allow-to-compile-test-Altera-FPGA-bridge-drivers/20170411-181401
> >config: m32r-allmodconfig (attached as .config)
> >compiler: m32r-linux-gcc (GCC) 6.2.0
> >reproduce:
> > wget https://raw.githubusercontent.com/01org/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> > chmod +x ~/bin/make.cross
> > # save the attached .config to linux build tree
> > make.cross ARCH=m32r
> >
> >All warnings (new ones prefixed by >>):
> >
> > In file included from include/linux/printk.h:329:0,
> > from include/linux/kernel.h:13,
> > from include/linux/delay.h:21,
> > from drivers/fpga/altera-freeze-bridge.c:18:
> > drivers/fpga/altera-freeze-bridge.c: In function 'altera_freeze_br_do_freeze':
> >>>drivers/fpga/altera-freeze-bridge.c:107:15: warning: format '%d' expects argument of type 'int', but argument 6 has type 'long unsigned int' [-Wformat=]
> > dev_dbg(dev, "%s %d %d\n", __func__, status, readl(csr_ctrl_addr));
> > ^
>
> The line above compiles cleanly for x86 and 32-bit ARM.
> Interestingly, the variable, status, is declared locally as an u32
> and is assigned by a
> call to readl(), and there is no warning. On x86 and 32-bit arm,
> readl(), is defined as returning u32, but on this m32r processor,
> readl() returns unsigned long, thus the warning.
>
> A possilbe fix to this warning is to declare another local u32, ctrl, and
> assign a value with a call to readl(). In other words, mimic what
> is done with the variable, status. While this would get rid of the
> warning, I can't help but think there is either a compiler problem
> or a problem with m32r.

I'd say this is a problem with how readl() is declared on m32r. On almost
all architectures readl() returns a u32 (which seems to be unsigned int
on all architectures).

Judging from a quick m32r allmodconfig build, it seems the warning
occurs at quite a few places in the kernel already and a quick Google
search also turns up quite some patches, where the same warning occured
[1], [2], [3].

[1] https://www.spinics.net/lists/linux-ide/msg53956.html
[2] https://lists.01.org/pipermail/kbuild-all/2016-September/025251.html
[3] https://www.spinics.net/lists/linux-bluetooth/msg70076.html

IMO the proper fix would probably be to fix the readl() implementation
on m32r.

>
> > include/linux/dynamic_debug.h:134:39: note: in definition of macro 'dynamic_dev_dbg'
> > __dynamic_dev_dbg(&descriptor, dev, fmt, \
> > ^~~
> >>>drivers/fpga/altera-freeze-bridge.c:107:2: note: in expansion of macro 'dev_dbg'
> > dev_dbg(dev, "%s %d %d\n", __func__, status, readl(csr_ctrl_addr));
> > ^~~~~~~
> > drivers/fpga/altera-freeze-bridge.c: In function 'altera_freeze_br_do_unfreeze':
> > drivers/fpga/altera-freeze-bridge.c:144:15: warning: format '%d' expects argument of type 'int', but argument 6 has type 'long unsigned int' [-Wformat=]
> > dev_dbg(dev, "%s %d %d\n", __func__, status, readl(csr_ctrl_addr));
> > ^
> > include/linux/dynamic_debug.h:134:39: note: in definition of macro 'dynamic_dev_dbg'
> > __dynamic_dev_dbg(&descriptor, dev, fmt, \
> > ^~~
> > drivers/fpga/altera-freeze-bridge.c:144:2: note: in expansion of macro 'dev_dbg'
> > dev_dbg(dev, "%s %d %d\n", __func__, status, readl(csr_ctrl_addr));
> > ^~~~~~~
> > drivers/fpga/altera-freeze-bridge.c:162:15: warning: format '%d' expects argument of type 'int', but argument 6 has type 'long unsigned int' [-Wformat=]
> > dev_dbg(dev, "%s %d %d\n", __func__, status, readl(csr_ctrl_addr));
> > ^
> > include/linux/dynamic_debug.h:134:39: note: in definition of macro 'dynamic_dev_dbg'
> > __dynamic_dev_dbg(&descriptor, dev, fmt, \
> > ^~~
> > drivers/fpga/altera-freeze-bridge.c:162:2: note: in expansion of macro 'dev_dbg'
> > dev_dbg(dev, "%s %d %d\n", __func__, status, readl(csr_ctrl_addr));
> > ^~~~~~~
> >
> >vim +107 drivers/fpga/altera-freeze-bridge.c
> >
> >ca24a648 Alan Tull 2016-11-01 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
> >ca24a648 Alan Tull 2016-11-01 13 * more details.
> >ca24a648 Alan Tull 2016-11-01 14 *
> >ca24a648 Alan Tull 2016-11-01 15 * You should have received a copy of the GNU General Public License along with
> >ca24a648 Alan Tull 2016-11-01 16 * this program. If not, see <http://www.gnu.org/licenses/>.
> >ca24a648 Alan Tull 2016-11-01 17 */
> >ca24a648 Alan Tull 2016-11-01 @18 #include <linux/delay.h>
> >ca24a648 Alan Tull 2016-11-01 19 #include <linux/io.h>
> >ca24a648 Alan Tull 2016-11-01 20 #include <linux/kernel.h>
> >ca24a648 Alan Tull 2016-11-01 21 #include <linux/of_device.h>
> >ca24a648 Alan Tull 2016-11-01 22 #include <linux/module.h>
> >ca24a648 Alan Tull 2016-11-01 23 #include <linux/fpga/fpga-bridge.h>
> >ca24a648 Alan Tull 2016-11-01 24
> >ca24a648 Alan Tull 2016-11-01 25 #define FREEZE_CSR_STATUS_OFFSET 0
> >ca24a648 Alan Tull 2016-11-01 26 #define FREEZE_CSR_CTRL_OFFSET 4
> >ca24a648 Alan Tull 2016-11-01 27 #define FREEZE_CSR_ILLEGAL_REQ_OFFSET 8
> >ca24a648 Alan Tull 2016-11-01 28 #define FREEZE_CSR_REG_VERSION 12
> >ca24a648 Alan Tull 2016-11-01 29
> >ca24a648 Alan Tull 2016-11-01 30 #define FREEZE_CSR_SUPPORTED_VERSION 2
> >ca24a648 Alan Tull 2016-11-01 31
> >ca24a648 Alan Tull 2016-11-01 32 #define FREEZE_CSR_STATUS_FREEZE_REQ_DONE BIT(0)
> >ca24a648 Alan Tull 2016-11-01 33 #define FREEZE_CSR_STATUS_UNFREEZE_REQ_DONE BIT(1)
> >ca24a648 Alan Tull 2016-11-01 34
> >ca24a648 Alan Tull 2016-11-01 35 #define FREEZE_CSR_CTRL_FREEZE_REQ BIT(0)
> >ca24a648 Alan Tull 2016-11-01 36 #define FREEZE_CSR_CTRL_RESET_REQ BIT(1)
> >ca24a648 Alan Tull 2016-11-01 37 #define FREEZE_CSR_CTRL_UNFREEZE_REQ BIT(2)
> >ca24a648 Alan Tull 2016-11-01 38
> >ca24a648 Alan Tull 2016-11-01 39 #define FREEZE_BRIDGE_NAME "freeze"
> >ca24a648 Alan Tull 2016-11-01 40
> >ca24a648 Alan Tull 2016-11-01 41 struct altera_freeze_br_data {
> >ca24a648 Alan Tull 2016-11-01 42 struct device *dev;
> >ca24a648 Alan Tull 2016-11-01 43 void __iomem *base_addr;
> >ca24a648 Alan Tull 2016-11-01 44 bool enable;
> >ca24a648 Alan Tull 2016-11-01 45 };
> >ca24a648 Alan Tull 2016-11-01 46
> >ca24a648 Alan Tull 2016-11-01 47 /*
> >ca24a648 Alan Tull 2016-11-01 48 * Poll status until status bit is set or we have a timeout.
> >ca24a648 Alan Tull 2016-11-01 49 */
> >ca24a648 Alan Tull 2016-11-01 50 static int altera_freeze_br_req_ack(struct altera_freeze_br_data *priv,
> >ca24a648 Alan Tull 2016-11-01 51 u32 timeout, u32 req_ack)
> >ca24a648 Alan Tull 2016-11-01 52 {
> >ca24a648 Alan Tull 2016-11-01 53 struct device *dev = priv->dev;
> >ca24a648 Alan Tull 2016-11-01 54 void __iomem *csr_illegal_req_addr = priv->base_addr +
> >ca24a648 Alan Tull 2016-11-01 55 FREEZE_CSR_ILLEGAL_REQ_OFFSET;
> >ca24a648 Alan Tull 2016-11-01 56 u32 status, illegal, ctrl;
> >ca24a648 Alan Tull 2016-11-01 57 int ret = -ETIMEDOUT;
> >ca24a648 Alan Tull 2016-11-01 58
> >ca24a648 Alan Tull 2016-11-01 59 do {
> >ca24a648 Alan Tull 2016-11-01 60 illegal = readl(csr_illegal_req_addr);
> >ca24a648 Alan Tull 2016-11-01 61 if (illegal) {
> >ca24a648 Alan Tull 2016-11-01 62 dev_err(dev, "illegal request detected 0x%x", illegal);
> >ca24a648 Alan Tull 2016-11-01 63
> >ca24a648 Alan Tull 2016-11-01 64 writel(1, csr_illegal_req_addr);
> >ca24a648 Alan Tull 2016-11-01 65
> >ca24a648 Alan Tull 2016-11-01 66 illegal = readl(csr_illegal_req_addr);
> >ca24a648 Alan Tull 2016-11-01 67 if (illegal)
> >ca24a648 Alan Tull 2016-11-01 68 dev_err(dev, "illegal request not cleared 0x%x",
> >ca24a648 Alan Tull 2016-11-01 69 illegal);
> >ca24a648 Alan Tull 2016-11-01 70
> >ca24a648 Alan Tull 2016-11-01 71 ret = -EINVAL;
> >ca24a648 Alan Tull 2016-11-01 72 break;
> >ca24a648 Alan Tull 2016-11-01 73 }
> >ca24a648 Alan Tull 2016-11-01 74
> >ca24a648 Alan Tull 2016-11-01 75 status = readl(priv->base_addr + FREEZE_CSR_STATUS_OFFSET);
> >ca24a648 Alan Tull 2016-11-01 76 dev_dbg(dev, "%s %x %x\n", __func__, status, req_ack);
> >ca24a648 Alan Tull 2016-11-01 77 status &= req_ack;
> >ca24a648 Alan Tull 2016-11-01 78 if (status) {
> >ca24a648 Alan Tull 2016-11-01 79 ctrl = readl(priv->base_addr + FREEZE_CSR_CTRL_OFFSET);
> >ca24a648 Alan Tull 2016-11-01 80 dev_dbg(dev, "%s request %x acknowledged %x %x\n",
> >ca24a648 Alan Tull 2016-11-01 81 __func__, req_ack, status, ctrl);
> >ca24a648 Alan Tull 2016-11-01 82 ret = 0;
> >ca24a648 Alan Tull 2016-11-01 83 break;
> >ca24a648 Alan Tull 2016-11-01 84 }
> >ca24a648 Alan Tull 2016-11-01 85
> >ca24a648 Alan Tull 2016-11-01 86 udelay(1);
> >ca24a648 Alan Tull 2016-11-01 87 } while (timeout--);
> >ca24a648 Alan Tull 2016-11-01 88
> >ca24a648 Alan Tull 2016-11-01 89 if (ret == -ETIMEDOUT)
> >ca24a648 Alan Tull 2016-11-01 90 dev_err(dev, "%s timeout waiting for 0x%x\n",
> >ca24a648 Alan Tull 2016-11-01 91 __func__, req_ack);
> >ca24a648 Alan Tull 2016-11-01 92
> >ca24a648 Alan Tull 2016-11-01 93 return ret;
> >ca24a648 Alan Tull 2016-11-01 94 }
> >ca24a648 Alan Tull 2016-11-01 95
> >ca24a648 Alan Tull 2016-11-01 96 static int altera_freeze_br_do_freeze(struct altera_freeze_br_data *priv,
> >ca24a648 Alan Tull 2016-11-01 97 u32 timeout)
> >ca24a648 Alan Tull 2016-11-01 98 {
> >ca24a648 Alan Tull 2016-11-01 99 struct device *dev = priv->dev;
> >ca24a648 Alan Tull 2016-11-01 100 void __iomem *csr_ctrl_addr = priv->base_addr +
> >ca24a648 Alan Tull 2016-11-01 101 FREEZE_CSR_CTRL_OFFSET;
> >ca24a648 Alan Tull 2016-11-01 102 u32 status;
> >ca24a648 Alan Tull 2016-11-01 103 int ret;
> >ca24a648 Alan Tull 2016-11-01 104
> >ca24a648 Alan Tull 2016-11-01 105 status = readl(priv->base_addr + FREEZE_CSR_STATUS_OFFSET);
> >ca24a648 Alan Tull 2016-11-01 106
> >ca24a648 Alan Tull 2016-11-01 @107 dev_dbg(dev, "%s %d %d\n", __func__, status, readl(csr_ctrl_addr));
> >ca24a648 Alan Tull 2016-11-01 108
> >ca24a648 Alan Tull 2016-11-01 109 if (status & FREEZE_CSR_STATUS_FREEZE_REQ_DONE) {
> >ca24a648 Alan Tull 2016-11-01 110 dev_dbg(dev, "%s bridge already disabled %d\n",
> >
> >:::::: The code at line 107 was first introduced by commit
> >:::::: ca24a648f535a02b4163ca4f4d2e51869f155a3a fpga: add altera freeze bridge support
> >
> >:::::: TO: Alan Tull <atull@xxxxxxxxxxxxxxxxxxxxx>
> >:::::: CC: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> >
> >---
> >0-DAY kernel test infrastructure Open Source Technology Center
> >https://lists.01.org/pipermail/kbuild-all Intel Corporation
> >
>

Next message: Peter Zijlstra: "Re: [PATCH v2 tip/core/rcu 0/13] Miscellaneous fixes for 4.12"
Previous message: Vivek Gautam: "Re: [PATCH V3 3/4] usb: dwc3: of-simple: Add support to get resets for the device"
In reply to: matthew . gerlach: "Re: [PATCH] fpga: allow to compile-test Altera FPGA bridge drivers"
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