openwrt/target/linux/ipq40xx/patches-4.14/088-0008-i2c-qup-use-the-complete-transfer-length-to-choose-D.patch
Piotr Dymacz 24de7c29e5 ipq40xx: backport I2C QUP driver changes from 4.17
Backport below changes for I2C QUP driver from v4.17:

  0668bc44a426 i2c: qup: fix copyrights and update to SPDX identifier
  7239872fb340 i2c: qup: fixed releasing dma without flush operation completion
  eb422b539c1f i2c: qup: minor code reorganization for use_dma
  6d5f37f166bb i2c: qup: remove redundant variables for BAM SG count
  c5adc0fa63a9 i2c: qup: schedule EOT and FLUSH tags at the end of transfer
  7e6c35fe602d i2c: qup: fix the transfer length for BAM RX EOT FLUSH tags
  3f450d3eea14 i2c: qup: proper error handling for i2c error in BAM mode
  08f15963bc75 i2c: qup: use the complete transfer length to choose DMA mode
  ecb6e1e5f435 i2c: qup: change completion timeout according to transfer length
  6f2f0f6465ac i2c: qup: fix buffer overflow for multiple msg of maximum xfer len
  f7714b4e451b i2c: qup: send NACK for last read sub transfers
  fbfab1ab0658 i2c: qup: reorganization of driver code to remove polling for qup v1
  7545c7dba169 i2c: qup: reorganization of driver code to remove polling for qup v2

This fixes various I2C issues observed on AP120C-AC board equipped with
Atmel/Microchip AT97SC3205T TPM module.

Tested-by: Christian Lamparter <chunkeey@gmail.com>
Signed-off-by: Piotr Dymacz <pepe2k@gmail.com>
2019-03-08 19:28:31 +01:00

55 lines
1.7 KiB
Diff

From 08f15963bc751bc818294c0f75a9aaca299c4052 Mon Sep 17 00:00:00 2001
From: Abhishek Sahu <absahu@codeaurora.org>
Date: Mon, 12 Mar 2018 18:44:57 +0530
Subject: [PATCH 08/13] i2c: qup: use the complete transfer length to choose
DMA mode
Currently each message length in complete transfer is being
checked for determining DMA mode and if any of the message length
is less than FIFO length then non DMA mode is being used which
will increase overhead. DMA can be used for any length and it
should be determined with complete transfer length. Now, this
patch selects DMA mode if the total length is greater than FIFO
length.
Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Reviewed-by: Austin Christ <austinwc@codeaurora.org>
Reviewed-by: Andy Gross <andy.gross@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
---
drivers/i2c/busses/i2c-qup.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
--- a/drivers/i2c/busses/i2c-qup.c
+++ b/drivers/i2c/busses/i2c-qup.c
@@ -1300,7 +1300,8 @@ static int qup_i2c_xfer_v2(struct i2c_ad
int num)
{
struct qup_i2c_dev *qup = i2c_get_adapdata(adap);
- int ret, len, idx = 0;
+ int ret, idx = 0;
+ unsigned int total_len = 0;
qup->bus_err = 0;
qup->qup_err = 0;
@@ -1326,14 +1327,14 @@ static int qup_i2c_xfer_v2(struct i2c_ad
goto out;
}
- len = (msgs[idx].len > qup->out_fifo_sz) ||
- (msgs[idx].len > qup->in_fifo_sz);
-
- if (is_vmalloc_addr(msgs[idx].buf) || !len)
+ if (is_vmalloc_addr(msgs[idx].buf))
break;
+
+ total_len += msgs[idx].len;
}
- if (idx == num)
+ if (idx == num && (total_len > qup->out_fifo_sz ||
+ total_len > qup->in_fifo_sz))
qup->use_dma = true;
}