On 1/25/20 10:59 AM, Pavel Machek wrote:
Hi!
[ Upstream commit e95fd518d05bfc087da6fcdea4900a57cfb083bd ]
Super-IO accesses may fail on a system with no or unmapped LPC bus.
Also, other drivers may attempt to access the LPC bus at the same time, resulting in undefined behavior.
Use request_muxed_region() to ensure that IO access on the requested address space is supported, and to ensure that access by multiple drivers is synchronized.
@@ -1644,9 +1654,21 @@ static int w83627thf_read_gpio5(struct platform_device *pdev) struct w83627hf_sio_data *sio_data = dev_get_platdata(&pdev->dev); int res = 0xff, sel;
- superio_enter(sio_data);
- if (superio_enter(sio_data)) {
/** Some other driver reserved the address space for itself.* We don't want to fail driver instantiation because of that,* so display a warning and keep going.*/dev_warn(&pdev->dev,"Can not read VID data: Failed to enable SuperIO access\n");return res;- }
- superio_select(sio_data, W83627HF_LD_GPIO5);
- res = 0xff;
This is strange. res is not actually assigned in the code above, so we have res = 0xff twice. Can we remove one of the initializations and do 'return 0xff' directly to make code more clear?
@@ -1677,7 +1699,17 @@ static int w83687thf_read_vid(struct platform_device *pdev) struct w83627hf_sio_data *sio_data = dev_get_platdata(&pdev->dev); int res = 0xff;
- superio_enter(sio_data);
- if (superio_enter(sio_data)) {
/** Some other driver reserved the address space for itself.* We don't want to fail driver instantiation because of that,* so display a warning and keep going.*/dev_warn(&pdev->dev,"Can not read VID data: Failed to enable SuperIO access\n");return res;- }
Direct "return 0xff" would make more sense here, too.
Please feel free to submit a patch to improve the upstream code.
Thanks, Guenter