Re: [PATCH v2] HID: i2c-hid: Use block reads when possible to save power
From: Sultan Alsawaf <hidden>
Date: 2020-07-01 15:00:17
Also in:
linux-i2c, lkml
On Wed, Jul 01, 2020 at 11:04:01AM +0300, Jarkko Nikula wrote:
On 6/29/20 8:43 PM, Sultan Alsawaf wrote:quoted
Hmm, for some reason in 5.8 I get the same problem, but 5.7 is fine. Could you try this on 5.7 and see if it works? In the meantime I'll bisect 5.8 to see why it's causing problems for me...I see the same issue on top of v5.7:
Try reverting my "i2c: designware: Only check the first byte for SMBus block read length" patch and apply the following change instead:
--- a/drivers/i2c/busses/i2c-designware-master.c
+++ b/drivers/i2c/busses/i2c-designware-master.c@@ -394,10 +394,12 @@ i2c_dw_read(struct dw_i2c_dev *dev) u32 flags = msgs[dev->msg_read_idx].flags; *buf = dw_readl(dev, DW_IC_DATA_CMD); - /* Ensure length byte is a valid value */ - if (flags & I2C_M_RECV_LEN && - *buf <= I2C_SMBUS_BLOCK_MAX && *buf > 0) { - len = i2c_dw_recv_len(dev, *buf); + if (flags & I2C_M_RECV_LEN) { + /* Ensure length byte is a valid value */ + if (*buf <= I2C_SMBUS_BLOCK_MAX && *buf > 0) + len = i2c_dw_recv_len(dev, *buf); + else + len = i2c_dw_recv_len(dev, len); } buf++; dev->rx_outstanding--;