| Message ID | 1603291814-240377-1-git-send-email-sagar.kadam@sifive.com |
|---|---|
| Headers | show |
| Series | fix i2c polling mode workaround for FU540-C000 SoC | expand |
Hello Peter, > -----Original Message----- > From: Peter Korsgaard <jacmet@gmail.com> On Behalf Of Peter Korsgaard > Sent: Wednesday, October 21, 2020 9:16 PM > To: Sagar Kadam <sagar.kadam@openfive.com> > Cc: linux-kernel@vger.kernel.org; linux-riscv@lists.infradead.org; linux- > i2c@vger.kernel.org; andrew@lunn.ch; Paul Walmsley ( Sifive) > <paul.walmsley@sifive.com>; palmer@dabbelt.com; > aou@eecs.berkeley.edu > Subject: Re: [PATCH v4 1/1] i2c: ocores: fix polling mode workaround on > FU540-C000 SoC > > [External Email] Do not click links or attachments unless you recognize the > sender and know the content is safe > > >>>>> "Sagar" == Sagar Shrikant Kadam <sagar.kadam@sifive.com> writes: > > > The FU540-C000 has a broken IRQ and support was added earlier > > so that it will operate in polling mode, but seems to work only > > in case interrupts property is missing from the i2c0 dt-node. > > This should not be the case and the driver should handle polling > > mode with the interrupt property present in i2c0 node of the > > device tree. > > So check if it's the FU540-C000 soc and enable polling mode master > > xfers, as the IRQ for this chip is broken. > > > Fixes commit c45d4ba86731 ("i2c: ocores: add polling mode workaround > > for Sifive FU540-C000 SoC") > > > Signed-off-by: Sagar Shrikant Kadam <sagar.kadam@sifive.com> > > LGTM, thanks. > > Acked-by: Peter Korsgaard <peter@korsgaard.com> > Thank you for the review and "Acked-by" BR, Sagar > -- > Bye, Peter Korsgaard
The polling mode workaround for the FU540-C000 on HiFive Unleashed A00 board was added earlier. The logic for this seems to work only in case the interrupt property was missing/not added into the i2c0 device node. Here we address this issue by identifying the SOC based on compatibility string and set the master xfer's to polling mode if it's the FU540-C000 SoC. The fix has been tested on mainline Linux 5.9 with a PMOD based RTCC sensor connected to I2C pins J1 header of the board. Log for reference # uname -a Linux buildroot 5.9.0-00001-ge092bd7 #1 SMP Wed Oct 21 06:19:31 PDT 2020 riscv64 GNU/Linux # i2cdetect -y 0 0 1 2 3 4 5 6 7 8 9 a b c d e f 00: -- -- -- -- -- -- -- -- -- -- -- -- -- 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 50: -- -- -- -- -- -- -- 57 -- -- -- -- -- -- -- -- 60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 6f 70: -- -- -- -- -- -- -- -- # i2cget 0 0x57 0 b -y 0xf9 # i2cset 0 0x57 0 0xa5 b -y # i2cget 0 0x57 0 b -y 0xa5 # i2cget 0 0x57 1 b -y 0xa9 # i2cset 0 0x57 1 0x9a b -y # i2cget 0 0x57 1 b -y 0x9a # i2cget 0 0x6f 0x20 b -y 0x98 # i2cset 0 0x6f 0x20 0x5a b -y # i2cget 0 0x6f 0x20 b -y 0x5a # i2cget 0 0x6f 0x5f b -y 0x55 # i2cset 0 0x6f 0x5f 0xa5 b -y # i2cget 0 0x6f 0x5f b -y 0xa5 # Without the fix here, it's observed that "i2cdetect -y 0" turns the system unresponsive, with CPU stall messages. Patch History: =============================== V4: -Used alternate implementation as suggested here: https://lkml.org/lkml/2020/10/15/513 -Removed TYPE_SIFIVE_REV0 field as it is no longer needed to set the polling mode and OCORES_FLAG_BROKEN_IRQ flag. V3: -Rectified typo as suggested here: https://lkml.org/lkml/2020/10/9/902 V2: -Incorporated changes as suggested by Peter Kosgaard https://lkml.org/lkml/2020/10/8/663 V1: Base version Sagar Shrikant Kadam (1): i2c: ocores: fix polling mode workaround on FU540-C000 SoC drivers/i2c/busses/i2c-ocores.c | 23 +++++++++++------------ 1 file changed, 11 insertions(+), 12 deletions(-)